Reading IRS Notices & Letters

There it is in the mailbox, between a grocery flyer and a credit card offer: a white envelope, a government seal, "Internal Revenue Service — Official Business." Your chest tightens before you've even touched it. Am I being audited? Did I do something wrong? Am I in trouble — the kind of trouble with handcuffs in it? If that's the feeling, you're in the majority. Almost everyone reads an IRS envelope as an accusation. And almost everyone is wrong about what's inside.

Here is the truth this lesson is built on, and it's worth saying before the envelope is even open. The IRS sends millions of notices every year, and the overwhelming majority are routine — a bill for a balance you already know about, a question a computer generated when two numbers didn't match, a confirmation that something changed, a PIN arriving on schedule. Each notice carries a code — printed right on it — that tells you exactly what it is and what clock is running. And almost none of them is an audit. Not the mismatch notice everyone panics over, not the bill, not even most of the scary-sounding ones. An audit is a specific thing with its own letters, and it's the next lesson. This lesson is about the mail — how to read it, how to answer it, and how to keep a piece of paper from hardening into a real problem simply because it sat unopened in a drawer.

Three filers carry the lesson, because three very different envelopes teach three very different skills. Gloria Simmons — 48, a home health aide in Memphis earning $29,000, raising her daughter Kiara on the Earned Income Tax Credit — gets the notice everyone fears most, a CP2000 saying she underreported income. Hers is the heart of the lesson, because the notice is *mostly* right, it's not her fault, and answering it well saves her real money. Nadia Okonkwo — the Columbus marketing coordinator you've followed since Lesson 1 — gets the most common notice of all, a CP14 bill for a small balance she genuinely owes. And Marcus Bell — the Atlanta rideshare-and-design freelancer — gets a mismatch notice that is simply *wrong*, which teaches the most empowering fact in this lesson: a notice is a proposal, and you're allowed to say no with evidence.

Before we open a single notice, learn the one rule that protects you from an entire industry of criminals: the IRS opens almost every conversation by letter, through the U.S. Postal Service. Not by phone. Not by text. Not by email, not by a social-media message, not by someone pounding on your door. The IRS's own guidance says it plainly: most contacts are initiated through regular mail, and the agency does not initiate contact by email, text message, or social media to ask for personal or financial information. If the very first you hear of a "tax problem" is a phone call, a voicemail threatening arrest, a text with a link, or an email with an attachment — it is not the IRS. Full stop.

Why does the IRS work this way? Partly law, partly proof. A mailed notice creates a record — of what was said, when the clock started, and where it was sent — that a phone call can't. Several notices in this lesson have legal force *only* because they were mailed to your "last known address" (a term we'll come back to, because it's why keeping your address current matters so much). Phone calls and visits do exist deeper in the process — a collector may call *after* letters have gone unanswered, and since 2023 even the IRS's field officers have generally had to send an appointment letter (Letter 725-B) instead of showing up unannounced. But the *opening move* is paper, essentially every time. That single fact lets you hang up on every "IRS agent" demanding immediate payment with total confidence — and we'll spend a whole section later on the impersonators who depend on you not knowing it.

IRS notices look bureaucratic, but they're bureaucratic in a *consistent* way — once you know where the bones are, every notice becomes readable in thirty seconds. Whatever the topic, the same elements sit in the same places: an identity block that says which notice this is and which year it's about, a summary that says what the IRS wants, a deadline that says when, and contact-and-rights boilerplate that says how to talk back. Learn the skeleton once and you'll never again read an IRS letter top to bottom in a panic, absorbing nothing.

Walk the skeleton once. The notice number lives in the corner of the page — the IRS's own decoder page says to look for the CP or LTR number in the right corner — and it is the key to everything: "CP" plus digits marks a computer-generated notice (CP stands for computer paragraph, a fossil from the 1960s systems that still assemble these), while "LTR" or "LT" marks a letter, often from the automated collection system. The notice date matters more than the day you happened to open the envelope, because every deadline counts from the printed date — a notice that sat a week in your mail pile has already spent a week of your clock. The tax year is easy to misread: a notice arriving in late 2026 is usually about your 2025 return, sometimes older, because the IRS's document matching runs a year or more behind (you'll see why in the CP2000 sections). Your SSN appears masked — last four digits only — which is one quick authenticity check. The amount and the ask live in a summary box near the top: real notices state a specific amount, a specific reason, and a specific action. And the back pages carry the machinery people skip but shouldn't: the phone number and hours for *that specific notice's* unit, payment instructions (any check goes to "United States Treasury" — never to anything else, a fact that unmasks a famous scam later in this lesson), and a reminder of your rights, including how to challenge what the notice says.

So here's the habit this whole lesson installs, the one that replaces the stomach-drop. You open the envelope and read exactly four things, in order: the notice number (what is this?), the tax year (about when?), the deadline (what clock is running?), and the ask (what do they want — money, information, or nothing?). Thirty seconds. You now know more than most people ever learn about their IRS mail, and you haven't had time to panic.

Then comes the two-minute verify, and it's the step that catches both scams and honest errors. Take the notice number to IRS.gov and search "Understanding your [number] notice" — the IRS keeps a plain-English page for every notice it sends, and the agency's own advice for a letter that seems suspicious is direct: if the letter doesn't appear in the notice search or looks off, call the IRS at 800-829-1040 to confirm it. Better still, sign in to your IRS Individual Online Account — the same account you may have used for payments in the withholding lesson — which shows digital copies of many notices, your balance by tax year, and your full payment history. A real notice about a real balance will be reflected there; a "notice" that exists only on the paper in your hand, demanding a payment your online account has never heard of, has just failed the test. Two minutes, and you've separated the genuine article from the counterfeit — before a single dollar or a single panicked phone call.

There are hundreds of notice codes, but you don't need hundreds — the mail sorts into five families, and knowing which family a notice belongs to tells you most of what you need before you've read a word of its body text. The routine family carries information and usually asks for nothing. The bill family says you owe and escalates politely, then less politely, if ignored. The mismatch family — the CP2000 and its relatives — proposes a change because a computer found a discrepancy. The verify family holds your refund until you prove you're you. And the audit family — genuinely rare — opens an examination, and belongs to the next lesson. Here's the map before we walk the big ones end to end.

The routine family deserves its own minute, because these are the notices most likely to hit your mailbox in an ordinary year — and every one of them is disarmable on sight. Notice how many involve no action at all, and how even the action items are small. That's the point of the table: calibration. When most of the family tree is this benign, the envelope stops being a threat and becomes what it actually is — mail.

Two rows up there deserve a highlight before we move to the heavyweights. First, the CP12/CP11 math-error pair carries a genuinely important right that almost nobody knows: when the IRS "corrects" your return this way, you have a 60-day window to contest the change — and if you let it pass, the IRS's own page warns that you lose the formal right to have the change reversed and to take it to Tax Court. A math-error notice feels final. It isn't — but only for sixty days. Second, notice what's *absent* from the whole routine family: any notice that opens an audit. The scary word simply doesn't live in this part of the tree, which is exactly why the thirty-second decode calms you down — most codes, once decoded, are this kind of mail.

Now the notice this lesson exists for. Remember from the income lessons that every W-2 and 1099 you receive is also filed with the IRS by whoever paid you — your employer, your bank, your broker, the gig platform. After filing season, IRS computers run the match: everything payers reported under your SSN, against everything you put on your return. The program that does this is called the Automated Underreporter, or AUR — and when the paper total exceeds what your return shows, and a human examiner agrees the gap looks real, out comes a CP2000. It is one of the most common substantive letters the IRS sends — the agency initiates millions of these compliance contacts a year, dwarfing actual audits — so if there is one notice worth learning deeply, it's this one.

Start with what a CP2000 is not, because the fear runs ahead of the facts. It is not a bill. The IRS's own page says so in exactly those words — "this notice isn't a bill" — and the amount inside is labeled a *proposed* amount due. Nothing has been assessed; nothing is owed yet; no collector is involved. And it is not an audit. The Taxpayer Advocate Service — the independent voice for taxpayers inside the IRS — describes the CP2000 as a proposal to correct your return, distinct from an examination. No one is combing through your life; a computer compared two columns of numbers, found a difference, and is *asking you about it*. The entire notice is, at heart, one question: "Our records show income your return doesn't. Are our records right?" Sometimes the answer is yes. Sometimes — as Marcus will show you — it's no. Either way, the notice is the beginning of a conversation, not the end of one.

Two quirks of the CP2000 confuse everyone, so let's kill them now. First, the delay. These notices routinely arrive a year or more after you filed — a tax year 2025 return filed in February 2026 typically draws its CP2000 in late 2026 or in 2027 — because the matching can only run after every payer's forms are in and processed. The delay isn't suspicion; it's plumbing. But it has a real cost: interest on any genuine shortfall has been quietly running since the original due date of the return, which is why even a modest mismatch arrives with an interest line attached. Second, the gentler cousin. Some mismatches draw a CP2501 instead — same matching program, but an open-ended "please explain" without a proposed dollar amount. If you get one, everything in the next five sections applies, minus the arithmetic: respond by the date, with documents. Answering a CP2501 well often means no CP2000 ever comes.

Gloria Simmons does hard, honest work — home health aide in Memphis, $29,000 a year, raising twelve-year-old Kiara on it. Filing season 2026, a coworker pointed her to a strip-mall shop called MaxRefund Express that promised "max refunds, fast." The man there was friendly and quick. He e-filed her 2025 return, took $500 in cash out of the refund as his fee, and never signed the return as its preparer — it went in marked *self-prepared*, which, as the preparer-vetting lesson will show you, is the single loudest warning sign in the business. A paid preparer who won't sign is called a ghost preparer, and he stays a ghost for a reason: when his work draws letters, they come to you, not him. (The omission you're about to watch surface wasn't the only liberty the shop took with her filings, either — the amending lesson catches the other one.)

One thing Gloria mentioned in that office matters here. Alongside her agency W-2, she'd brought a second form — a 1099-NEC for $6,800 from CareBridge Registry LLC, a staffing registry that books her for private weekend caregiving shifts and treats its caregivers as independent contractors. The man waved it off: "those little ones don't get reported." That sentence — friendly, confident, and false — is the whole reason this lesson's centerpiece exists. The registry filed its copy of that 1099-NEC with the IRS, the way payers do. Her return, as he filed it, showed only the $29,000. The refund came out to $5,683, the biggest she'd ever seen, and for a while it felt like a blessing: withholding back, the Earned Income Tax Credit, the refundable piece of the Child Tax Credit.

Thirteen months after that filing — the ghost shop has even done her 2026 return by now, quick and friendly as ever — the envelope arrives. Notice CP2000, tax year 2025, notice date March 16, 2027 — and in the summary box, proposed amount due: $2,780.56, with a response date of April 15, 2027. Her first thought is the one this lesson opened with: *I'm being audited. I'm in trouble. Maybe the kind with police in it.* So run her through the thirty-second decode before anything else. The number: CP2000 — the mismatch family, a proposal, not a bill, not an audit. The year: 2025, the ghost preparer's return. The clock: thirty days, a real deadline but a survivable one. The ask: respond — agree, or explain. Nobody is accusing Gloria of a crime; a computer noticed that CareBridge reported $6,800 her return never mentioned, and it is asking. The fear is real, but the paper is smaller than the fear. Now let's read every box of it.

Here is Gloria's notice — the same layout the real Automated Underreporter unit mails, condensed to one specimen. Where and what: a CP2000 arrives by U.S. mail from the IRS campus that handles your region (the return address names it — Gloria's comes from the Memphis-area AUR unit), and if you've opted in, a digital copy appears in your IRS Online Account. Mode note for e-filers: it makes no difference how you filed — e-filed returns are matched exactly like paper ones, and the notice is paper either way. Read the specimen top to bottom, then we'll take the three sections one at a time.

The masthead and summary (top of page 1). Every skeleton bone from earlier is here: CP2000 in the corner, tax year 2025, the March 16 notice date that starts the clock, her SSN masked to the last four. Two additions are CP2000-specific. The AUR control number identifies her case inside the underreporter system — she'll write it on everything she sends, so her response and her file find each other. And the contact line lists the AUR unit's toll-free number and a fax number; this notice is answered by mail, by fax, or through the IRS's online Documentation Upload Tool — you send scans or photos (JPG, PNG, or PDF) and get a confirmation of receipt, no envelope required. The summary box carries the two numbers that matter: proposed amount due $2,780.56 and respond by April 15, 2027. IS: a proposal and a deadline. DOES for Gloria: tells her the size of the problem and the time she has. MATTERS: because *proposed* means the conversation is still open — and the date means it won't stay open by itself.

The income-comparison table (the heart of the notice). One row per mismatched item, four columns: the payer's name, the form type, what your return showed, what the payer reported. Gloria's has a single row — CareBridge Registry LLC · Form 1099-NEC · nonemployee compensation · shown on return: $0 · reported to IRS by others: $6,800 · difference: $6,800. IS: the computer's evidence, laid out payer by payer. DOES for Gloria: shows her *exactly* which form her return missed — no mystery, no fishing expedition. MATTERS: because this table is where you fact-check the IRS. Payers make mistakes — duplicated forms, wrong amounts, income that belongs to someone else's SSN, forms for income that was actually reported on another line of your return. Gloria reads the row and recognizes it instantly: the weekend registry work the ghost preparer waved away. The table is right. But *whether the table is right is always your first question* — Marcus's row, three sections from now, is wrong.

The tax-computation section (page 2). The notice then rebuilds her return with the $6,800 included, line by line: self-employment tax appears (the registry treats her as a contractor, so this is contractor income), her AGI rises, her taxable income rises, and — this is the part that shocks people — her credits are recomputed. The CP2000 doesn't just add tax on new income; it re-runs every income-sensitive credit at the new income level. Gloria's EITC shrinks. The refundable piece of her Child Tax Credit shifts. The notice shows each change as a labeled line — you can trace every dollar of the $2,780.56, and in the next section we will, because a number you can decompose is a number that can't frighten you. IS: the corrected return, in miniature. DOES: turns "you owe $2,780.56" into arithmetic. MATTERS: because the recomputation only includes what the IRS *knows about* — a point that becomes Gloria's partial-agreement lever two sections from now.

Let's earn Gloria's number, because the difference between "the IRS says I owe $2,780.56" and "I can see exactly where $2,780.56 comes from" is the difference between panic and a plan. All figures here are tax year 2025 — the year under the microscope — computed with 2025's verified rules: a $23,625 head-of-household standard deduction, the $2,200-per-child Child Tax Credit with up to $1,700 refundable, and the one-child EITC that phases out at 15.98 cents per dollar once income passes $23,350.

The return as the ghost preparer filed it. Wages $29,000, nothing else. Standard deduction $23,625 leaves $5,375 of taxable income — tax of $538, sitting entirely in the 10% bracket. The Child Tax Credit wipes that $538 to zero, and its refundable remainder — the Additional Child Tax Credit — pays out $1,662. Her EITC at $29,000 of earned income computes to $3,421 (she's $5,650 past the $23,350 phase-out start, so the maximum $4,328 gives back 15.98% of that overage — about $907). Add her $600 of withholding: $600 + $3,421 + $1,662 = $5,683 refunded. That's the number that felt like a blessing.

The return as the AUR computer rebuilds it. Add $6,800 of contractor income and three things move at once. First, self-employment tax appears: $961 — the registry paid her as a contractor, so she owes both halves of Social Security and Medicare on it (15.3% of $6,800 × 92.35% = $961), and the notice grants the standard half-SE-tax deduction of $481 alongside. Second, income tax rises: AGI becomes $35,319, taxable income $11,694, tax $1,168 — still fully absorbed by the Child Tax Credit, but absorbing $1,168 of it instead of $538 leaves less to refund, so the refundable piece falls from $1,662 to $1,032 — $630 less. Third, and biggest in feel: the EITC recomputes at the higher income — $11,975 past the phase-out start now — and lands at $2,414, $1,007 less than the return claimed. Stack the three: $961 of new tax + $1,007 of EITC + $630 of ACTC = $2,598. That's the overpaid refund being asked back — not a fine, not a penalty: the difference between the refund she got and the refund the corrected return supports.

Two readings of that equation, and both matter. The hard one: $2,780.56 is real money against a $29,000 income — more than a month's take-home — and it lands because a stranger with a storefront wanted a bigger number on a screen. The IRS is not wrong to send this notice; the return really did omit income. The softer one: no part of this number is punishment. There's no fraud penalty on it, no accusation in it — at this size the automatic accuracy penalties don't even apply — just tax that was always owed, credits recalculated to what the law actually supports, and interest for the year the money sat on the wrong side. And one more thing, which is the hinge of Gloria's whole story: the computer rebuilt her return using *only what it could see*. It cannot see her car. It cannot see the miles she drove to those weekend clients. It doesn't know she's entitled to a small-business deduction on this income. The proposal is honest — and it is still too high, which is exactly what the response form is for.

The last page of every CP2000 is the Response form, and it's the most important page in this lesson: the piece of paper that keeps the conversation open. It asks one question — do you agree with the proposed changes? — and gives you three honest ways to answer it. Here is Gloria's, walked box by box.

Option 1 — "I agree with all changes." Checking this and signing is called consenting to the assessment: you're telling the IRS to make its proposal real, and the proposed amount becomes an actual balance. IS: a consent, not a confession. DOES: ends the matter cleanly — no further notices, no escalation. MATTERS: two ways. If the notice is simply right (the classic case: a forgotten savings-account 1099-INT), agreeing fast is the cheapest exit — interest stops accruing once you pay, and you do NOT file an amended return for the items on the notice; the CP2000 process handles the correction itself (the IRS asks for a 1040-X only if you have *other*, unrelated corrections — you'd write "CP2000" across the top and send it with the response). And if you agree but can't pay in full, agreeing and arranging are separate acts — you can consent to the change and simultaneously request a payment plan; owing money you can't immediately pay is a solved problem with its own lesson ahead. Note the signature rule: on a joint return, *both* spouses sign. One signature on a two-name return bounces.

Option 2 — "I partially agree" (Gloria's box). IS: the yes-but answer — the income is mine, the recomputation is incomplete. DOES: sends the case back to a human with your evidence attached: a signed statement of what you agree with and what you don't, plus documentation. MATTERS: because AUR's computer only taxes what it sees, and it never sees your deductions. Gloria agrees the $6,800 is her income — and disagrees with taxing it as if earning it cost nothing, because she drove 1,114 logged miles to those weekend clients and is entitled to the qualified-business-income deduction on the profit. Her attachment is a filled-in Schedule C showing the income *with* its expenses — the practitioner's standard move: show the IRS what the return should have looked like. Option 3 — "I don't agree with any changes." IS: the full no. DOES: same mechanics — signed explanation plus proof. MATTERS: when the notice itself is wrong — the 1099 is duplicated, the amount is wrong, the income isn't yours (a real identity-theft tell), or it was already reported on a line the computer didn't credit. That's Marcus's box, coming shortly.

Three boxes, three doors — and the right door is a matter of *facts*, not strategy. This isn't a negotiation where you open low; it's a records check where you answer true. Here's the decision, distilled.

What happens after you send it? The AUR unit reviews your response — allow a couple of months; this pipeline is measured in weeks, not days — and answers in kind. If it accepts your explanation entirely, you get a letter saying the inquiry is closed with no change to your return: done, and it happens constantly (payer errors are a routine finding). If it accepts part, you get a recomputed notice — a fresh CP2000 with revised, smaller numbers and a fresh response window; that's not the IRS haggling, it's the arithmetic redone with your facts in it, and it's exactly what Gloria is about to receive. If it stands its ground, you get a letter explaining why, and the path continues toward the 90-day letter — where your rights actually *expand*, as you'll see. Notice what every branch has in common: a response keeps you inside the conversation. Silence is the only move that ends it — and silence is the one branch where the proposal hardens into a real assessed debt untouched by any facts you never sent.

Gloria checks Option 2 and builds her yes-but on paper. Her statement is three sentences long — plain language is all these ever need: *the $6,800 from CareBridge Registry is my income and I agree it belongs on my return; I do not agree with the tax computed on it, because I had business expenses driving to client homes and I qualify for the qualified business income deduction; my corrected Schedule C and mileage log are attached.* With it goes the log — 1,114 miles of dated entries to her weekend clients, worth $780 at 2025's 70-cents-per-mile standard rate (the recordkeeping lesson's discipline, paying off in cash) — and a Schedule C showing the income the way an honest preparer would have filed it: $6,800 of receipts, $780 of expenses, $6,020 of profit.

Run the corrected math the way the AUR examiner will. Self-employment tax on $6,020 instead of $6,800: $851, not $961. The QBI deduction — 20% of the net self-employment profit — takes another $1,119 off taxable income, something the computer never offers on its own. Income tax lands at $988, still fully absorbed by the Child Tax Credit; the refundable piece recovers to $1,212; the EITC, recomputed at $34,594 instead of $35,319, recovers to $2,534. New bottom line: $2,188 of tax change instead of $2,598, and interest of $153.75 instead of $182.56. The recomputed notice that comes back to her reads $2,341.75 — $438.81 less than the original proposal, for one honest statement and two attachments.

Read the moral at both depths. Small: a mileage log and a one-page schedule were worth $438.81 — evidence pays. Large: the CP2000's number is an opening statement, not a verdict, computed from exactly the facts the IRS could see and no others. The people who lose money to underreporter notices aren't usually the ones who owe the most; they're the ones who either pay the first number unexamined or ignore the letter entirely. Gloria did neither. What she cannot do is make $2,341.75 appear by April — a real problem, with a real solution: the same response machinery lets her ask for an installment agreement, and the collections lesson walks her through it (spoiler: the IRS approves these routinely, and the failure-to-pay penalty actually drops by half while a payment plan is in effect). One more door her response leaves open, quietly: because Tennessee has no wage income tax, Gloria is spared the *state* echo — but most filers aren't. States receive the same federal adjustment data, and a federal CP2000 that sticks typically triggers a state notice or an obligation to amend the state return. If you live in an income-tax state, budget for the echo.

Now the other direction — because teaching you to respond would be malpractice without teaching you that sometimes the correct response is no. Marcus Bell's CP2000 arrives two weeks after Gloria's (the same spring-2027 matching wave, same tax year 2025), proposing $947.19. His income-comparison table shows the rideshare platform's Form 1099-K — the card-payment form you met in the gig lesson, which platforms must file once payments run past $20,000 across more than 200 transactions (a threshold the 2025 tax law restored after years of on-again-off-again lower limits). The platform reported $23,400 of gross ride payments. Marcus's Schedule C showed total receipts of $77,500 against everyone's paper total of $81,000. Difference: $3,500 of "unreported income."

Except Marcus didn't underreport a dollar — he *under-described*. Here's the mechanism, and it is the single most common way honest gig workers draw this notice. A 1099-K reports the gross, unadjusted amount — the IRS's own guidance lists what it is *not* reduced by: fees, credits, refunds. Riders paid $23,400 through the app; the platform kept $3,500 in commissions and fees; $19,900 hit Marcus's bank. When Marcus built his Schedule C from bank deposits, he wrote $19,900 into his receipts — so his line 1 came in $3,500 under the paper trail, and his expenses came in $3,500 under reality, because he never listed fees he never saw leave. His profit was perfectly correct — $62,000 either way — but profit isn't what the computer matches. It matches *gross receipts against information returns*, and his didn't reconcile.

So Marcus checks Option 3 — I don't agree with any changes — and attaches the platform's annual tax summary, which states the gross fares and the $3,500 of commissions right on its face, plus a corrected Schedule C showing $81,000 of gross receipts and $19,000 of expenses: identical $62,000 profit, identical tax, proposed change: zero. The AUR unit accepts it — this is a pattern examiners see daily — and the inquiry closes with no change. Cost of the error: one letter, one response, some adrenaline. The prevention, which is cheaper still: report the gross, deduct the fees. Gross receipts on Schedule C line 1 should carry the platform's gross figure; the fees go in as an ordinary expense line. Same profit, same tax — but now the computer's match reconciles and no letter is ever born. (And if a 1099-K is *actually* wrong — duplicated, or not yours — the IRS says to ask the issuer for a corrected form; the IRS itself can't fix a payer's paperwork.)

Now follow the road not taken. Suppose Gloria had done the human thing — shoved the CP2000 in a drawer and hoped. No reply by April 15. What comes next is not a raid and not an arrest; it's a second letter, heavier than the first: Notice CP3219A, the Statutory Notice of Deficiency. Tax people call it the 90-day letter, and it is the most legally significant piece of mail in this entire lesson.

"Statutory" is the tell: this notice is a formal step written into the tax code itself. Before the IRS can convert its proposal into an actual assessed debt over your objection, the law makes it send you this — a formal statement of the deficiency it intends to assess, and with it, a right no earlier notice carried: 90 days to petition the United States Tax Court (150 days if the notice is addressed to you outside the country). File that petition in time and the IRS cannot assess or collect while the court considers your case — you get a judge *before* you pay, which is the Tax Court's entire reason for existing. Let the 90 days pass, and the deficiency is assessed, the amount becomes a legal debt, and the collection machinery — CP14, the reminder ladder, eventually the levy notices — starts up. You can still pay and sue for a refund afterward, but the easy courtroom door has closed.

Two facts about this deadline deserve italics, bold, and a highlighter. The IRS cannot extend it. Not won't — *can't*; its own page says exactly that, because the deadline is statutory and no examiner has authority over it. Every other date in this lesson bends a little — the CP2000 window takes extensions, late responses get read, payment dates restructure. This one is stone. And the last day to petition is printed on the notice itself. You never have to count 90 days on a calendar and hope; the date is in the box. When you hear tax professionals say "never ignore a stat notice," this is the whole reason: it's the only notice where silence permanently forfeits a courtroom.

Walk its boxes. The deficiency statement — IS: the amount the IRS has now formally determined, carried forward from the unanswered CP2000. DOES: names the number that will be assessed on day 91. MATTERS: it's no longer labeled "proposed." The last-day-to-petition box — IS: a printed date. DOES: sets the one immovable clock in this lesson. MATTERS: everything; circle it the moment the envelope opens. Form 5564, the waiver — IS: an enclosed consent form. DOES: signing it says "I agree after all — assess it now," which ends the 90-day wait and stops interest from growing through it. MATTERS: it's the right move *only* if, on reflection, the IRS is simply correct — never sign it as an appeasement. The still-open side door — the notice itself says you can keep sending the IRS information during the 90 days, and cases do resolve this way; but the page carries a warning in plain terms: doing so does not extend the petition deadline. The examiner reading your late documents and the courthouse clock are two different machines, and only a petition stops the second one.

"Petition the United States Tax Court" sounds like something that requires a law firm and a retainer you can't afford. Here is what it actually requires, verified against the court's own guidance for self-represented petitioners. The filing fee is $60 — waivable if you genuinely can't pay it. The petition is a short form you can complete and file electronically through DAWSON, the court's online system, from your kitchen table (received by 11:59 p.m. Eastern on the deadline day; a mailed petition counts by its postmark — the tax code's timely-mailed-is-timely-filed rule, which is also why certified mail is your friend). You may represent yourself — the court is built for it, and thousands of taxpayers do it every year.

And for disputes like Gloria's there's a purpose-built lane: the small tax case election, or "S case," available when the amount in dispute is $50,000 or less for each year. S cases run on relaxed evidence rules and less formal procedure — closer to a conversation with a judge than a courtroom drama — with one real trade-off: an S-case decision cannot be appealed, by you or by the IRS. For a $2,700 dispute, that trade is usually easy. One more honest fact that surprises people: most petitions never reach trial at all. Filing one routes your case to the IRS's settlement machinery — typically the Independent Office of Appeals — and the great majority resolve there. The petition isn't a declaration of war; it's the act that preserves your seat at the table while the talking continues. The full road — Appeals, the settlement process, what a trial actually looks like — is the disputes-and-appeals lesson at the end of this arc; free and low-cost representation for exactly this situation appears in this lesson's help stack below.

Step back now from proposals and courtrooms to the most ordinary notice the IRS sends — the plain bill — because odds are this is the one you'll actually meet, and it deserves a filer whose story is boring in the best way. Nadia, you'll remember from the withholding lesson, re-tuned her W-4 in mid-2025 chasing a fatter paycheck instead of an interest-free-loan refund — and overshot a little. Her 2025 return, filed on time in April 2026, showed a $480 balance due. She paid $200 with the return, meant to send the rest "next paycheck," and life did what life does. In late June, the envelope: Notice CP14, tax year 2025, amount due $287.35, pay by July 13, 2026.

The CP14 is the notice and demand — the tax code's formal first bill, sent when a return shows more tax than payments. It isn't a proposal (the CP2000's word) and it isn't a threat (the collection ladder's job); it's an invoice with a breakdown. And its first virtue is that it's *checkable*: before paying any tax bill, spend the two-minute verify from earlier — pull up your IRS Online Account, look at the balance for that tax year and your payment history. This matters for a mundane reason the IRS prints right on these notices: payments and bills cross in the mail. If you paid within the last 21 days, the bill may simply not reflect it yet — the notice says so — and the correct move is to check your account, not to pay twice. (A double payment isn't lost — it becomes a credit or refund — but untangling it costs weeks.) Nadia checks: $200 credited in April, $280 outstanding. The bill is real and right.

Walk her three money lines, because this is where a bill teaches. Tax: $280.00 — IS: the unpaid remainder of her April balance. DOES: names the principal. MATTERS: it should match your own records — this is the line you verify. Failure-to-pay penalty: $4.20 — IS: the late-payment penalty you met in concept back in the withholding lesson, now with its real rate: 0.5% of the unpaid tax per month or part of a month, and April-to-late-June touches three months, so 1.5% of $280. DOES: prices the lateness. MATTERS: it keeps accruing monthly until paid (to a 25% ceiling) — but it also *shrinks* to 0.25% monthly while an approved payment plan is running, and only jumps (to 1%) deep in the ignored-collections road. The full penalty story — including getting them removed — is the abatement lesson. Interest: $3.15 — IS: 68 days of daily-compounded interest at the quarter's 6% underpayment rate. DOES: prices the time. MATTERS: unlike penalties, interest is set by formula each quarter (federal short-term rate plus 3 points) and essentially can't be waived — it's the one meter that always runs. Total: $287.35, and here's the small print worth knowing: pay within the notice's window — 21 calendar days (10 business days when a bill is $100,000 or more) — and that figure settles it; run past it and the meters keep adding.

Nadia pays the $287.35 through IRS Direct Pay that evening — no stamp, instant confirmation number, saved to her tax folder — and her story ends there, which is the point of her story. A CP14 answered inside its window is a complete non-event: no ladder, no levies, a $7.35 tuition bill for the lesson "pay the whole balance when you file." Two footnotes complete the picture. If she *couldn't* have paid it all, the same notice points to payment plans — short-term arrangements cost nothing to set up online, and the collections lesson covers the whole menu; the worst move at any size of bill is silence, not slowness. And if her math had disagreed with the IRS's — a payment missing from her account, a number that didn't reconcile — the move is the number on the notice plus her documentation, *before* the due date: bills, like proposals, are answerable.

What if Nadia had drawered it? Not because she's reckless — because the money wasn't there, and shame does what shame does: each envelope after the first gets harder to open. Here is exactly what that road looks like, because knowing the ladder's shape is what breaks the shame spiral. The IRS escalates *slowly, in writing, with warnings at every rung* — nobody goes from a $287 bill to a seized bank account, and every rung has an exit.

Read the rungs. CP501 and CP503 are reminders — same balance, growing interest, increasingly firm language; the CP503 starts warning about a federal tax lien (the public claim against your property you met in the ladder caption — a lien is the *claim*, a levy is the *taking*). CP504, "Notice of Intent to Levy," is where people's blood runs cold, and it's worth reading precisely: at this rung the IRS may seize your state tax refund — and, for the largest debts, certify you for passport denial — but your paycheck and bank account are *not yet* reachable. The law requires one more letter first. That letter is LT11 (or Letter 1058 — same notice, different IRS office sending it): the *final* notice of intent to levy, and the only one that arrives bolted to a hearing right, which gets its own section next. Two truths to hold together about this ladder: months pass climbing it, with the failure-to-pay penalty ticking (and eventually tripling to 1% monthly) and interest compounding the whole way — and yet every exit works at every rung. A payment plan set up at the CP503 stage looks exactly like one set up at the CP14 stage, just with a few more dollars of penalty baked in. The ladder punishes silence, never lateness of the change of heart.

The LT11 / Letter 1058 says, in nearly these words: we intend to seize your property or rights to property — wages and other income, bank accounts, business and personal assets, state refunds, even Social Security benefits — and it is the letter people describe when they say the IRS "came after" someone. Read it with this lesson's eyes instead: the reason this letter exists at all is that the law forbids levying your wages or accounts until you've received it and been offered a hearing. The final notice isn't the IRS pouncing; it's the legally mandated last exit before the toll booth — and the exit is generous.

The exit is called a Collection Due Process hearing — CDP — and you claim it by filing Form 12153 within 30 days of the notice (the deadline, like every deadline in this lesson, counts from the notice date; the form goes to the hearing address printed on the notice itself, not the payment address). What a timely CDP request buys, straight from the form's own instructions: levy action is generally prohibited while your hearing is pending, the ten-year collection clock pauses, and — this is the part that elevates it above every informal phone call — when the Appeals office issues its determination, you can take *that* to Tax Court. At the hearing itself (usually just a phone call with an appeals officer, nothing like a courtroom) you can put every real-world solution on the table: an installment agreement, an offer in compromise, currently-not-collectible hardship status, innocent-spouse relief, "my payments were misapplied," — the collections and appeals lessons take each of these in full. Miss the 30 days? The door doesn't slam: within one year of the notice you can still request an equivalent hearing — the same conversation with Appeals, but without the levy pause and without the Tax Court ticket. Real, but a visibly weaker instrument — one more illustration of this lesson's oldest rule: the earlier you answer, the more rights you're holding when you do.

Everything this lesson has taught about specific notices compresses into a discipline that works for all of them — the seven habits that turn IRS mail from a threat into paperwork. This is the section to bookmark.

1. Open it the day it arrives — and never ignore a dated letter. Every clock in this lesson runs from the notice date, not the day you find your courage. The CP2000's thirty days, the stat notice's ninety, the CDP's thirty, the CP14's twenty-one: all of them were already running while the envelope sat unopened. Opening it costs nothing and is the single highest-value move in this lesson.
2. Decode before you react: number, year, clock, ask. Thirty seconds. Most notices decode to "routine"; the rest decode to a specific, known process with a specific, known response — which you now know.
3. Verify before you pay or panic. Look the notice number up on IRS.gov; check your IRS Online Account for the balance and the digital copy. This one habit simultaneously catches scams (a demand your account has never heard of), crossed-in-the-mail bills (you already paid), and IRS errors (Marcus).
4. Respond in writing, by the date, through a channel that leaves a receipt. Certified mail with return receipt, the fax confirmation page, or the Documentation Upload Tool's confirmation. Phone calls are fine for questions — but a phone call leaves no proof you responded, and proof is the point. Send copies, never originals; put the notice's control number on every page.
5. Keep everything. The notice, your response, the receipts, the follow-up letters — one folder per tax year, forever alongside the return it concerns. Your recordkeeping lesson called this the paper trail that wins disputes; notices are exactly the disputes it meant.
6. Need more time? Ask — before the deadline. The CP2000 unit grants extensions for the asking (mail, fax, or the number on the notice). Payment deadlines restructure into plans. The only deadline in this lesson that never moves is the 90-day letter's — which is why rule 1 exists.
7. Keep your address current — and expect the state echo. File Form 8822 when you move (a notice mailed to your last known address is legally effective even if you never see it — people have lost 90-day windows to a forwarding lapse). And when a federal notice changes your return, assume your state will hear about it: states receive federal adjustment data and send their own bills; amending the state return yourself is usually cheaper than waiting for its letter.

Every fear this lesson has worked to shrink — the audit that isn't, the arrest that never happens, the deadline panic — is exactly the raw material impersonation scammers mine. IRS impersonation is a perennial headliner on the IRS's own Dirty Dozen scam list, and it works by *sounding like this lesson's subject matter*: official codes, urgent clocks, official-looking seals. You are now equipped to see through every version of it, because you know how the real thing behaves.

Maybe you're not reading this lesson out of curiosity. Maybe there's an envelope — or a stack of them — in a drawer right now, months old, radiating dread. Maybe a deadline in this lesson is one you've already missed, and every section has tightened the knot in your stomach a little. Stop and hear this first: you are not in the trouble your fear says you're in, and none of the doors that matter most are locked. The tax system is genuinely confusing, IRS mail is genuinely frightening by design of circumstance if not intent, and freezing in the face of it is a human response so common the IRS has entire procedures built around late answers. Set the self-blame down; here is what you can still do, for each place you might be standing.

• You ignored a CP2000 and the 30 days passed. Respond anyway, now — late responses are read, and if the deficiency hasn't yet been assessed your facts can still change the outcome. If a CP3219A has arrived, its 90-day clock is your new spine: petition if you dispute, and keep working the response channel in parallel (the notice itself invites it).
• You missed the 90-day letter too, and the amount got assessed. The prepayment courtroom is gone, but the merits aren't: ask the IRS for audit reconsideration — a request to re-examine an assessment in light of documents it never saw (your mileage log, your fee statement). Collections alternatives (payment plan, hardship status) run in parallel so the ladder pauses while the merits get another look. The audits and appeals lessons walk both roads.
• Bills piled up and you're somewhere on the ladder — CP501, CP503, CP504, even the final notice. Every exit still works: a payment plan today looks the same as one six months ago, minus some penalty dollars. If the LT11/1058 is in hand, the 30-day CDP window is precious — file Form 12153 before anything else. If even that's passed, the one-year equivalent hearing remains, and so does every payment arrangement.
• You paid a fake "IRS" — a gift-card demand, a wire, a check to a P.O. box. This is theft done to you by professionals, not a mistake you made. Report it today (TIGTA, the FTC, your bank — the How-to-Report box above), then breathe: your actual IRS account is untouched by what a criminal invoiced you, and your real tax standing is whatever your real notices say.
• You've been too afraid to even check what you owe. Start smaller than an envelope: sign in to your IRS Online Account and just *look*. Balances by year, notices, payment history — the same dashboard this lesson has used as a verification tool works as an inventory of exactly where you stand, with no hold music and no one watching you find out.

And one more, for the reader carrying Gloria's particular weight — a return someone else botched in your name, a refund spent before the letter came, a balance that isn't payable this month: her whole arc through the next lessons exists for you. The notice was survivable. The balance is negotiable. The system that sent the scary mail also runs payment plans, penalty relief, hardship statuses, appeals, and a free advocate service — and you've now read the map to all of them. You are one honest response form away from being back inside the process, and the process is far more boring, and far more forgiving, than the fear.

Notices come with a built-in help ladder, and climbing it in order saves both money and weeks. Here is the honest version, including the rungs that are free and the caveats nobody prints on the letterhead.

1. The notice itself — its number, its phone line, its instructions. Every notice names the exact unit that sent it and the number that reaches it; for a question about *this* notice, that beats the general IRS line every time. Pair it with the notice's page on IRS.gov and, for a CP2000, Publication 5181 (the IRS's own plain-language walkthrough of the underreporter process). Honest caveat: IRS phone service is seasonal and thin — waits are long and many calls never connect in peak months — which is one more argument for answering in writing, where your response can't be put on hold.
2. Your IRS Online Account — the self-service rung. Balances by year, digital copies of many notices, payment history, transcripts, and payment-plan applications, 24 hours a day. Most verification questions in this lesson ("did they get my payment?" "is this notice real?" "what do I actually owe?") answer themselves here in minutes.
3. The Low Income Taxpayer Clinics (LITCs) — free representation that specializes in exactly this lesson. Independent of the IRS, funded to represent lower-income taxpayers (generally income up to 250% of the federal poverty level, with disputes typically $50,000 or under) in CP2000 responses, audits, collections, CDP hearings, and Tax Court itself — Gloria's situation is their bread and butter, in any language. Find one through the Taxpayer Advocate Service's LITC directory. VITA — the free preparation program you know from earlier lessons — is honest about its limits here: notice response and representation are generally beyond its scope; LITCs are the notice specialists.
4. The Taxpayer Advocate Service (TAS) — the free advocate inside the IRS. For when the process itself breaks: a hardship the normal channels won't move fast enough for (a levy about to hit rent money), a response lost twice, a case going in circles. File Form 911 or call 877-777-4778. TAS is the backstop, not the front door — but when you need it, it has real authority to make the machine move.
5. A CPA, Enrolled Agent, or tax attorney — the paid rung, priced to the stakes. For a $287 CP14, overkill. For a five-figure CP2000, a Statutory Notice of Deficiency with real money attached, or anything involving fraud language, professional help pays for itself — and for a 90-day letter specifically, get it *early* in the window, not day 85. In Tax Court you may self-represent, and attorneys and specially admitted practitioners (including many LITC representatives) can appear for you.
6. Appeals and the Tax Court — the formal rights, always the last rung and never gone. The Independent Office of Appeals reviews disputes fresh; the Tax Court hears deficiency cases before you pay and CDP determinations after. Both get their full lesson at the end of this arc — the thing to hold now is that the ladder never dead-ends: every notice in this lesson connects, eventually, to an independent reviewer.

Ten questions that arrive with nearly every IRS envelope, answered plainly — each pointing back to the section where the full story lives.

• "I got an IRS letter — am I being audited?" Almost certainly not. Audits are rare and announced by specific examination letters (next lesson). The overwhelming bulk of IRS mail is routine notices, bills, and computer-match questions — and even the scary-famous CP2000 is explicitly not an audit; it's a proposal generated by document matching, asking you to confirm or correct.
• "Why is the IRS writing to me about a return I filed almost two years ago?" Because document matching can only run after every employer's and payer's forms are processed — so underreporter notices for a tax year typically go out a year or more after that year's returns were filed. The delay is plumbing, not suspicion. Its one real cost: interest on any true shortfall has been running since the return's due date.
• "The notice says I owe money. Do I just pay it?" Verify first, then decide. Check the notice against your own return and your IRS Online Account. A CP14 that matches your records: pay it (within its 21-day window, ideally). A CP2000: never "just pay" — it's a proposal, its number can be too high (Gloria's was, by $429), or entirely wrong (Marcus's was, by all of it). Paying an unverified number is how people pay twice, or pay scammers.
• "What if I can't pay what the notice asks?" Then respond anyway — the amount you owe and the speed you pay it are two separate problems. Agreeing to a correct CP2000, or receiving a correct bill, while simultaneously requesting a payment plan is normal, routine, and penalty-*reducing* (the failure-to-pay rate halves during an approved plan). The collections lesson covers every arrangement; silence is the only unaffordable option.
• "I don't agree with the notice. What do I do — and will fighting it make things worse?" Respond by the date, in writing, with documents — the response form exists precisely for disagreement, and using it triggers nothing bad. No flag, no audit, no grudge: examiners close cases with "no change" every day when the evidence supports it. The system's whole design assumes some proposals are wrong; Marcus's zero is what disagreement looks like when it works.
• "What's this '90-day letter' everyone talks about in such a serious voice?" The Statutory Notice of Deficiency (CP3219A): the formal last step before the IRS assesses a disputed amount, and the only notice whose deadline is absolutely immovable. Ninety days (printed on the notice) to petition the Tax Court if you dispute it — the one courtroom you get before paying. It earns the serious voice; it's also survivable by anyone who reads the date and acts inside it.
• "The IRS called/texted/emailed me about a debt. How do I know if it's real?" If it's the first you've heard of the debt — it isn't real. The IRS opens by postal mail, and its real payment demands never involve gift cards, wire transfers, crypto, or arrest threats. Verify against your online account, and report the contact to TIGTA. (Deep in a real collection case, calls can occur — but by then you'd have a drawerful of the letters this lesson taught you to read.)
• "I already paid — why am I getting a bill?" Usually: the payment and the bill crossed in the mail. The CP14 itself allows for payments made in the last 21 days; your online account shows what's actually been credited. Confirm there before paying again. If a payment is genuinely missing or misapplied, call the number on the notice with your confirmation number — misapplied payments are a standard, fixable case (and a valid thing to raise all the way up at a CDP hearing).
• "Will a federal notice affect my state taxes?" Very likely, if you're in an income-tax state. States receive federal adjustment data, and a CP2000 change that sticks typically produces a state assessment months later — some states bill automatically if you don't amend within their window. Cheaper to amend your state return yourself once the federal change is final. (No-income-tax-state filers like Gloria and the Reyes family are spared this echo.)
• "Does responding to a notice restart or extend anything against me?" No — responding preserves rights; it doesn't waive them. A CP2000 response doesn't extend the assessment statute; a CDP request pauses collection, not the other way around. The clocks that matter (30 days, 90 days) run whether or not you engage. Engagement is pure upside — which is this whole lesson in one sentence.

You've read three specimens box by box and walked the whole family tree. Now run the drill you'll actually use at the mailbox. The decoder below holds the eight notices this lesson taught: pick the code off any envelope — real or imagined — and it answers the four questions of the thirty-second decode: what is this, is it an audit, what clock is running, and what's the next action. It opens on Gloria's CP2000 so you can re-trace her story; switch codes and watch how completely the answers change.

As you flip through the codes, watch for the pattern that makes the whole lesson portable: every single answer to "is this an audit?" is no — and every single "next action" starts with reading a date off the notice and answering through a channel that leaves a receipt. When a real envelope arrives — this year, or in ten — you won't remember every line of this lesson. You'll remember the drill: number, year, clock, ask; verify; respond in writing; keep the copy. That's the entire skill, and you now have it.

Every term this lesson introduced, in one place — the vocabulary of reading and answering IRS mail.

• Notice / letter number — the code (CP + digits for computer-generated notices, LTR/LT for letters) printed in the corner of every IRS mailing; the key you look up on IRS.gov to decode what you're holding.
• Notice date — the printed date on a notice; every response clock counts from it, not from the day you opened the envelope.
• Last known address — the address from your most recent return or Form 8822; a notice mailed there is legally effective even if you never receive it — the reason movers file Form 8822.
• Automated Underreporter (AUR) — the IRS program that matches payer-filed W-2s and 1099s against filed returns and generates CP2000 notices from the mismatches.
• CP2000 — the underreporter notice: a payer-by-payer comparison of what was reported to the IRS versus what your return showed, with a recomputed tax and a proposed amount due. Not a bill; not an audit; 30 days to respond (60 from abroad).
• CP2501 — the gentler cousin: same matching program, an explain-this letter with no dollar proposal attached.
• Proposed amount due — the CP2000's bottom line if its changes stand: tax increase, plus any credit reductions, plus interest computed from the return's due date to 30 days past the notice date.
• Response form — the last page of a CP2000: agree / partially agree / disagree, with signature lines (both spouses on a joint return) and instructions for mail, fax, or upload.
• Documentation Upload Tool — the IRS's online channel (irs.gov/upload) for answering many notices with scans or photos (JPG/PNG/PDF), with an on-screen confirmation of receipt.
• Recomputed notice — the revised CP2000 the IRS sends after accepting part of your response: the same proposal re-run with your facts, and a fresh response window.
• CP14 (notice and demand) — the first bill for a balance due: tax, penalty, and interest itemized, generally payable within 21 calendar days of the notice date (10 business days at $100,000+).
• Failure-to-pay penalty — 0.5% of unpaid tax per month or part-month (capped at 25%); halves to 0.25% during an approved payment plan; rises to 1% after a final levy-notice warning goes unheeded. (Removing penalties is the abatement lesson.)
• Underpayment interest — the meter that always runs: federal short-term rate + 3 points, set quarterly (6–7% through 2026), compounded daily from the return's due date; charged on penalties too, and essentially not waivable.
• CP501 / CP503 — the reminder rungs of the collection ladder: unpaid balance, firmer language, lien warnings beginning.
• CP504 (Notice of Intent to Levy) — the rung where the IRS may seize your state tax refund (and start passport certification for large debts); wages and bank accounts still require the final notice.
• Federal tax lien vs. levy — the lien is the public legal claim against your property; the levy is the actual taking (wages, accounts). Lien first, levy later, warnings throughout.
• LT11 / Letter 1058 / CP90 — the Final Notice of Intent to Levy and Notice of Your Right to a Hearing — the letter the law requires before wages or accounts can be levied, carrying the CDP right.
• Collection Due Process (CDP) hearing — the hearing right attached to the final levy notice (and the lien-filing notice): request within 30 days on Form 12153; levy generally pauses; the determination is appealable to Tax Court.
• Equivalent hearing — the same Appeals conversation requested after the 30 days but within 1 year: no levy pause, no Tax Court review of the outcome.
• CP3219A / Statutory Notice of Deficiency / "90-day letter" — the formal, law-required notice before a disputed amount is assessed: 90 days (150 abroad) to petition the U.S. Tax Court; the last day is printed on the notice; the IRS cannot extend it.
• Form 5564 (waiver) — the consent form enclosed with a deficiency notice: signing agrees to immediate assessment — right only if the IRS is simply correct.
• U.S. Tax Court / DAWSON / S case — the prepayment court for deficiency disputes: $60 filing fee (waivable), electronic filing through DAWSON, self-representation welcome, and a simplified small-case lane ("S case") for disputes of $50,000 or less per year — with no appeal from an S-case decision.
• Audit reconsideration — the post-assessment request to re-examine a deficiency in light of documents the IRS never saw; the merits door that stays open after the 90-day window closes.
• Math-error 60-day right — the window (CP11/CP12) to contest an automatic "correction" to your return before the easy reversal path and Tax Court rights on it lapse.
• TIGTA — the Treasury Inspector General for Tax Administration: the watchdog that takes IRS-impersonation reports (tigta.gov · 800-366-4484).