IRS Form 4549-A: How to Respond, Protest, or Petition Tax Court

IRS Form 4549-A, Income Tax Examination Changes, is the report a revenue agent gives you after auditing a flow-through entity (a partnership, S corporation, or trust) when the resulting adjustments have to be picked up on your personal return. It’s a proposal, not a bill. What you do with it in the next 30 days decides whether you keep the right to appeal, to go to Tax Court without paying first, or to negotiate the number down at all.

What the Form Actually Says

The layout is straightforward. The top identifies you, the entity, the tax period, and the return examined. The core is a three-column table showing amounts “As Reported,” the agent’s proposed “Adjustments,” and the resulting “Corrected” figures. Schedule A handles income adjustments; Schedule B handles deductions and credits. Each line cites the tax code section the agent relied on.

The form itself is a summary. The reasoning lives in Form 886-A, Explanation of Items, which the agent typically prepares alongside the 4549-A.1Internal Revenue Service. Internal Revenue Manual 4.10.8 – Report Writing Read the 886-A before you read anything else. That’s where you find out whether the agent’s facts are right and whether the legal authority actually supports the adjustment.

The tax computation section applies the appropriate rates to the corrected income, subtracts the tax originally shown, and produces the proposed deficiency. Proposed penalties appear below that, and the form notes that interest will accrue. Nothing on the form has been assessed yet.

Why the Signature Line Is the Whole Ballgame

Signing Form 4549-A is a written waiver of the restrictions on assessment under IRC 6213. You are giving up your right to receive a Statutory Notice of Deficiency and your right to petition the U.S. Tax Court before paying.2Office of the Law Revision Counsel. 26 USC 6213 – Restrictions Applicable to Deficiencies; Petition to Tax Court Tax Court is the only forum where you can challenge the deficiency without paying it first. Every other route (federal district court, Court of Federal Claims) requires you to pay in full and then sue for a refund.3Internal Revenue Service. Understanding Your CP3219N Notice

Before signing anything, verify the arithmetic that got the entity’s adjustment onto your personal return. The agent applies your K-1 ownership percentage to the entity-level change. A wrong percentage is a common error and worth checking against the entity’s actual ownership records for the year under exam.

Agree or Disagree

You have two paths. There is no middle.

Agree. Sign the form and return it by the deadline. The IRS assesses the deficiency and sends a Notice and Demand for Payment (the actual bill). Interest continues to run from the original due date of the return until you pay. This is the fast path and costs you nothing in professional fees, but it closes every door to reducing the number.

Disagree. Don’t sign. The IRS will then issue a 30-day letter, formally a Notice of Proposed Deficiency, which gives you the right to file a written protest with the IRS Independent Office of Appeals.4Taxpayer Advocate Service. Letter 525 Audit Report/Letter Giving Taxpayer 30 Days to Respond If you miss that 30-day window, the IRS moves straight to the 90-day letter and you lose access to Appeals entirely.

Which path makes sense depends on the size of the proposed deficiency, how solid the agent’s legal position looks after you’ve read the 886-A, and what fighting will cost you. Agreeing is rational when the agent is clearly right or the amount is small. Disagreeing is rational when the agent misapplied the law or worked from wrong facts, or when the deficiency is large enough that a partial reduction through Appeals would more than pay for the effort.

Filing a Protest With Appeals

The written protest is your ticket to Appeals. You have 30 days from the date of the 30-day letter, and you mail it to the IRS address shown on that letter, not directly to Appeals.5Internal Revenue Service. Preparing a Request for Appeals A protest must include:

  • Your name, address, taxpayer identification number, and the tax periods involved.
  • A statement identifying each specific adjustment you are contesting.
  • The facts that support your position on each contested item.
  • The legal authority you rely on to dispute the agent’s conclusions.
  • A signed declaration under penalties of perjury that the facts in your protest are true and correct.

If the total proposed additional tax and penalties for each tax period is $25,000 or less, you can send a Small Case Request instead: a brief letter identifying the changes you disagree with and why, without the formal structure.5Internal Revenue Service. Preparing a Request for Appeals

An Appeals Officer reviews the agent’s report and your protest independently and has authority to settle based on the “hazards of litigation,” meaning the realistic chance the IRS would win in court. Many disputes settle here for less than the full proposed number. If you can’t reach agreement, the IRS issues the Statutory Notice of Deficiency.

Fast Track Settlement Before the 30-Day Letter

There’s an earlier option worth knowing about. Fast Track Settlement is a voluntary mediation program where an Appeals Officer acts as a neutral mediator between you and the examining agent, targeting resolution within 60 days for small businesses and individuals (120 days for large businesses).6Internal Revenue Service. Fast Track You and the agent jointly complete Form 14017 to apply. The mediator can propose settlement terms but can’t force either side to accept, and if Fast Track doesn’t resolve the issue you keep your right to file a protest and go through the normal Appeals process.7Internal Revenue Service. Publication 5022 – Fast Track Settlement

To qualify, all issues have to be fully developed: the agent has finished the exam work and you’ve turned over the relevant documentation. Correspondence audits, cases already docketed in court, and issues covered by prior closing agreements don’t qualify. For a flow-through audit where the facts are settled and the disagreement is about legal treatment of a few items, Fast Track can shave months off the traditional route.

The 90-Day Letter and the Tax Court Deadline

If Appeals doesn’t resolve the dispute (or if you skipped Appeals by missing the 30-day deadline), the IRS issues the Statutory Notice of Deficiency, the “90-day letter.” You then have 90 days (150 if you’re outside the United States) to file a petition with the U.S. Tax Court.2Office of the Law Revision Counsel. 26 USC 6213 – Restrictions Applicable to Deficiencies; Petition to Tax Court

This deadline is hard. Miss it and the IRS assesses the tax and starts collection. Your only remaining option is to pay in full and sue for a refund. The prepayment protection Tax Court offers is the practical reason many taxpayers refuse to sign the 4549-A in the first place.

Penalties and Interest Riding Along

Two additions typically inflate what you actually owe.

The most common is the 20% accuracy-related penalty under IRC 6662, which applies to any part of an underpayment caused by negligence, disregard of the rules, or a substantial understatement of income tax.8Office of the Law Revision Counsel. 26 USC 6662 – Imposition of Accuracy-Related Penalty on Underpayments “Substantial understatement” means the understatement exceeds the greater of 10% of the correct tax or $5,000. For a return claiming the Section 199A qualified business income deduction, the threshold drops to 5%. You can defeat the penalty by showing reasonable cause and good faith, by showing you had substantial authority for the position, or in some situations through adequate disclosure on the return. Raise those defenses in your protest if the penalty is on the report.

Interest is the other one, and it isn’t negotiable. The IRS cannot waive or reduce it, not even through Appeals. Interest runs from the original due date of the return (not from when the IRS caught the problem) at the federal short-term rate plus three percentage points, compounded daily and adjusted quarterly.9Internal Revenue Service. Interest Rates Remain the Same for the First Quarter of 2026 The individual underpayment rate is 7% for the first quarter of 2026 and drops to 6% for the second quarter.10Internal Revenue Service. Internal Revenue Bulletin 2026-8 On a deficiency from a return filed years ago, interest alone can rival the tax, and every month the dispute drags on it grows.

Check the Statute of Limitations Before You Do Anything

The IRS generally has three years from the date you filed your return to assess additional tax.11Internal Revenue Service. Time IRS Can Assess Tax The clock starts when the return is filed, not when the year ends. Exceptions:

When you look at the 4549-A, confirm the assessment deadline hasn’t already passed. If it has, the IRS cannot legally assess the tax no matter what the audit found. This defense gets missed more often than you’d expect in long-running entity exams, because the individual owner’s statute can expire on a different date than the entity’s.

A Note on BBA Partnership Audits

Not every partner in an audited partnership will see a Form 4549-A. Under the Bipartisan Budget Act of 2015, effective for tax years beginning in 2018, most partnerships are audited under a centralized regime where the IRS assesses tax at the partnership level rather than chasing individual partners.13Office of the Law Revision Counsel. 26 USC 6225 – Partnership Adjustment by Secretary The partnership either pays the imputed underpayment itself or makes a push-out election under IRC 6226, which shifts the adjustments to the partners of the reviewed year, who report them on Form 8978.14Internal Revenue Service. BBA Partnership Audit Process

Partnerships with 100 or fewer eligible partners can elect out of the BBA regime.15Internal Revenue Service. Elect Out of the Centralized Partnership Audit Regime Those that elect out, along with S corporations and trusts, still go through the traditional flow-through examination that produces a 4549-A for each owner. If you’re a partner in a BBA partnership that didn’t elect out, the process described in this article isn’t the one you’re in; the partnership representative handles the audit and you may not receive individual notice at all.

If You Already Signed

Signing isn’t always final. You can request audit reconsideration if you have new information the agent didn’t consider during the exam. To qualify, you must have filed the original return, the assessment must still be unpaid (or involve disputed credit reversals), and you must present information that’s actually new.16Internal Revenue Service. Internal Revenue Manual 4.13.1 – Examination Audit Reconsideration Process

Reconsideration is not a do-over. You can’t rerun the same arguments, and the IRS will not reopen cases resolved by a closing agreement, a compromise, or a Tax Court decision. But if you locate documentation that substantiates a deduction the agent disallowed, send the request and the supporting records to the IRS office that handled the original examination.