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CP3219A· Underreporter (CP2000 family)

CP3219A — Statutory notice of deficiency (90-day letter, AUR)

Statutory Notice of Deficiency issued by the Automated Underreporter unit. The IRS proposes a tax deficiency based on a mismatch between reported income and third-party data, and notifies you of the right to petition the U.S. Tax Court.
IRC §6213(a)2026-05-08Form 55642026-05-08
Category
Underreporter
Urgency
Time-sensitive
Response window
90 days
Key form
Form 5564

A short, often fixed window — act promptly.

Why the IRS sent this

Unresolved CP2000 / CP2501 underreporter mismatch escalated to a statutory notice of deficiency.

Response window · stated on irs.gov

90 days
Notice receivedday 0
Respond byday 90

Within 90 days, either (a) sign Form 5564 to agree, (b) provide additional documentation to dispute, or (c) file a petition with the U.S. Tax Court. No extensions are available for the 90-day Tax Court window.

What to do

Required action

Within 90 days, either (a) sign Form 5564 to agree, (b) provide additional documentation to dispute, or (c) file a petition with the U.S. Tax Court. No extensions are available for the 90-day Tax Court window.

Key form: Form 5564 — verify the current revision on irs.gov/forms-pubs before filing.

Appeal path

U.S. Tax Court — 90-day petition

U.S. Tax Court (90-day petition window). Concurrent informal dispute with the IRS is allowed.

IRC §6213(a)

Notes from the primary source

Often called the 90-day letter for underreporter cases. Equivalent function to Letter 3219 but issued from the AUR program. Form 5564 (the agreement form) is enclosed with your physical notice — the IRS does not host a separate landing page for it.

Go deeper

Educational pillars for this notice

Calm-corrective

Only the IRS can resolve your notice

We are not a CPA firm, not a law firm, not an Enrolled Agent firm, and not affiliated with the IRS. We don't accept payments on your behalf, settle your debt, or call the IRS for you. What we do: explain what your notice means, point you to the right IRS form, cite the statute that authorizes the action, and surface the appeal path. Then you call the number on the notice, file the form, or hire a licensed professional.

Related notices

Likely next or sibling codes

Source

Verified against the official IRS detail page on irs.gov/individuals/understanding-your-cp3219a-notice. Always re-verify against the IRS page before acting.