IRS Notice CP22A: Math Error on Your Return
The IRS says you made a math error and adjusted your return. The difference from an audit: the IRS can assess tax immediately. You have 60 days to request abatement and restore your Tax Court rights.
What Makes CP22A Different
CP22A triggers IRC §6213(b) — the math error statute. This gives the IRS the power to ASSESS THE TAX IMMEDIATELY without issuing a statutory notice of deficiency. You do not get the normal pre-payment Tax Court appeal. This is why the 60-day abatement request is critical: if you file it, the IRS must abate the assessment and follow normal deficiency procedures (30-day letter → 90-day letter → Tax Court). If you miss the 60 days, you lose that right — you must pay the tax, then sue for refund. CP22A is the most procedurally dangerous of the routine return-change notices.
Common CP22A Math Errors
Tax Table Error
Incorrect tax calculated from the tax tables — wrong filing status bracket, wrong number of exemptions, tax table line misread.
EITC Miscalculation
Earned Income Tax Credit computed incorrectly — wrong number of qualifying children, investment income over the limit, income above phaseout threshold.
Credit Phaseout Errors
Child Tax Credit, education credits, saver's credit — all phase out with income. Filing the wrong income number triggers automatic adjustment.
IRA Deduction Exceeded
Claiming an IRA deduction that exceeds the statutory limit for your income, filing status, and retirement plan coverage.
Standard Deduction Wrong
Claiming the wrong standard deduction for your filing status, age, or blindness status — the IRS computer catches this instantly.
Dependent SSN Mismatch
The dependent's name and SSN don't match IRS records — the dependent's exemption and related credits are disallowed automatically.
The 60-Day Abatement Request: Step by Step
Call the IRS phone number on your CP22A immediately — state clearly that you disagree with the math error determination and are requesting abatement under IRC §6213(b)(2). Get the representative's name and ID number
Send a written request for abatement to the address on the notice — cite IRC §6213(b)(2) explicitly. State each math error you dispute, explain why the IRS calculation is wrong, and attach supporting documents (original return, corrected worksheets, schedules)
Request that the assessment be abated and that the IRS follow normal deficiency procedures — this forces the IRS to either concede the issue or issue a statutory notice of deficiency (90-day letter) giving you Tax Court rights
If the IRS grants abatement, you will receive correspondence confirming the assessment is reversed. The IRS then typically sends a 30-day letter (proposed changes) or a CP2000 (underreported income) and must give you a 90-day letter before reassessing
If the IRS denies abatement, you still have options: pay the tax and file a refund claim (Form 843) followed by a refund suit in U.S. District Court or the Court of Federal Claims
Frequently Asked Questions
Is a CP22A really a math error or did I get audited?
A CP22A is a math error under §6213(b), not an audit. The distinction is procedurally critical: math errors bypass normal deficiency procedures, while audits require a 90-day letter before assessment. However, the IRS's definition of 'math error' is broader than most taxpayers expect — it includes not just arithmetic mistakes but also claiming credits/deductions without the required schedules or forms, exceeding statutory limits, and dependent conflicts. If you believe the IRS is using 'math error' to avoid giving you audit rights, the 60-day abatement request forces them to either defend the error or follow normal audit procedures.
What if the IRS is right about the math error — but the underlying data on my return is wrong?
If your return contained incorrect information (not just a math error but wrong income, wrong filing status, wrong dependents), you should file Form 1040-X (Amended U.S. Individual Income Tax Return) to correct the underlying error. The CP22A math error correction only fixes the arithmetic — if the numbers you gave the IRS were wrong in the first place, amending is the correct path. Pay the adjusted amount or set up a payment plan while the amendment processes.
Can I go to Tax Court over a CP22A?
Not directly. Under §6213(b), the IRS can assess a math error without issuing a 90-day letter, so you have no pre-assessment Tax Court right. You must first request abatement within 60 days. If abatement is granted, the IRS must issue a statutory notice of deficiency, which gives you Tax Court petition rights. If abatement is denied or you missed the 60-day window, you must pay the tax, file an administrative refund claim, and if denied, sue for refund in U.S. District Court or the Court of Federal Claims.