If your tax refund came in at roughly half what you expected, the most likely reason is that a government agency took part of it to pay a debt, or the IRS adjusted your return during processing. Past-due child support, defaulted federal student loans, prior-year federal or state tax balances, and disallowed credits like the EITC or Child Tax Credit are the usual causes. The specific reason is always spelled out in a notice mailed to you, and that notice determines what you can do next.
Start With the Notice
Before doing anything else, check the IRS “Where’s My Refund” tool at irs.gov or in the IRS2Go app. It will show the adjusted refund amount, but not the reason. The reason comes by mail, and the specific letter tells you where the money went.
- A CP12 notice means the IRS corrected an error on your return and your refund changed as a result.1Internal Revenue Service. Understanding Your CP12 Notice
- A CP11 notice means the correction wiped out your refund and left you owing money.2Internal Revenue Service. Understanding Your CP11 Notice
- A CP49 notice means the IRS applied your refund to a tax balance you owed from a prior year.3Internal Revenue Service. Understanding Your CP49 Notice
- A letter from the Bureau of the Fiscal Service means your refund was reduced to pay a non-tax debt like child support or a defaulted student loan. It lists the original refund, the amount taken, and the agency that received it.4Internal Revenue Service. Topic No. 203, Reduced Refund
Hold onto every notice. The reference numbers and deadlines printed on them are what you need to contest the reduction or resolve the underlying debt.
Refund Offsets for Debts You Owe
The Bureau of the Fiscal Service runs the Treasury Offset Program, which intercepts federal payments — including tax refunds — to pay delinquent debts owed to federal and state agencies. This program is separate from the IRS, so the IRS itself may not know the details of the debt. The Bureau also charges an administrative fee on each offset.5Office of the Law Revision Counsel. 31 USC 3716 – Administrative Offset
The debts that most often eat into a refund are:
- Past-due child support reported by a state.
- Federal student loans that have been in default for more than 120 days, once referred by the Department of Education.
- Other past-due, legally enforceable non-tax debts owed to federal agencies, such as overpaid federal benefits.
- Unpaid state income taxes, in states with reciprocal offset agreements.
- State unemployment benefits that were overpaid to you.
The Order Debts Are Paid
Federal law fixes the order in which your refund is applied when you owe more than one debt. First, the IRS covers any prior-year federal income tax you owe. Next comes past-due child support, then debts owed to other federal agencies, then past-due state income tax, and finally state unemployment overpayments.6Office of the Law Revision Counsel. 26 USC 6402 – Authority To Make Credits or Refunds Whatever remains after all offsets is what you receive. If you owe in several categories, your refund can be split across them until it runs out — which is one common reason a refund shrinks to about half.
Finding Out Which Agency Took Your Refund
If a non-tax offset reduced your refund and you want to know which agency claimed it, call the Treasury Offset Program’s automated line at 800-304-3107. The system will identify the agency.7Bureau of the Fiscal Service. Treasury Offset Program – Contact Us The Treasury Offset Program itself cannot discuss the debt or negotiate with you. To dispute the amount or arrange a payment plan, you have to contact the referring agency directly.8Bureau of the Fiscal Service. FAQs for Debtors in the Treasury Offset Program
Prior-Year IRS Balances
Before your refund ever reaches the Treasury Offset Program, the IRS checks its own records for unpaid federal income tax from earlier years. If you owe, the IRS applies your current overpayment — plus any interest that has accrued on it — to that balance automatically.6Office of the Law Revision Counsel. 26 USC 6402 – Authority To Make Credits or Refunds You will get a CP49 notice showing how much was used and which year it went toward.3Internal Revenue Service. Understanding Your CP49 Notice
The amount taken is often much larger than the original tax due, because failure-to-pay penalties and daily-compounding interest have added up over the years the debt sat unpaid. The failure-to-pay penalty runs 0.5% per month up to 25% of the balance,9Internal Revenue Service. Failure to Pay Penalty and the interest rate for the first quarter of 2026 is 7%.10Internal Revenue Service. Quarterly Interest Rates If the offset does not cover the full old balance, the remainder keeps accruing.
Math Errors and Income Mismatches
Every return runs through an automated check. If the arithmetic on a schedule does not add up, or if the wages and other income you reported do not match the W-2s and 1099s that employers and financial institutions sent to the IRS, the agency corrects the return and adjusts your refund without opening a formal audit.11Office of the Law Revision Counsel. 26 USC 6213 – Restrictions Applicable to Deficiencies; Petition to Tax Court You receive a CP12 notice showing the changes and the new refund amount.1Internal Revenue Service. Understanding Your CP12 Notice
Overstating your estimated tax payments has the same effect: if you claim more than the IRS shows on your account, your refund drops to reflect what was actually paid in.
You Have 60 Days to Push Back
If you disagree with a math-error adjustment, you have 60 days from the date on the notice to ask the IRS to reverse it. Miss that window and the adjustment becomes final. You lose the right to challenge it in Tax Court, and your only remaining option is to pay the assessed amount, file a refund claim, and if necessary sue in federal district court or the Court of Federal Claims.11Office of the Law Revision Counsel. 26 USC 6213 – Restrictions Applicable to Deficiencies; Petition to Tax Court Read the notice as soon as it arrives; the exact response deadline is printed on it.
Disallowed Credits
The Earned Income Tax Credit and the Child Tax Credit are two of the largest credits on a return, so losing one of them can easily halve a refund. The Child Tax Credit is worth up to $2,200 per qualifying child, and the EITC can reach roughly $8,000 for filers with three or more children.12Internal Revenue Service. Child Tax Credit When the IRS decides you do not qualify, or reduces the credit, the refund shrinks accordingly.
The most common reason is a problem with the qualifying child. To count for both the EITC and CTC, a child generally must have lived with you in the United States for more than half the tax year.13Internal Revenue Service. Qualifying Child Rules When two people claim the same child, such as parents who share custody, the IRS awards the credit to one filer and adjusts the other. Age, relationship, and income limits can also disqualify you.
If a Credit Was Disallowed in a Previous Year
If the IRS disallowed your EITC, CTC, or American Opportunity Tax Credit before, you cannot just claim it again the next year. You have to file Form 8862 to show you now meet the rules.14IRS. About Form 8862, Information To Claim Certain Credits After Disallowance Skip that form and the credit gets denied automatically, which is another way refunds get cut in half. You only need to file it once, unless you are disallowed again.
Marketplace Health Insurance Repayments
If you bought health coverage through the Marketplace and received advance premium tax credits to lower your monthly premiums, you have to reconcile them on Form 8962 when you file. If your actual income for the year came in higher than the estimate you gave the Marketplace, or your household size changed, the advance payments can exceed what you were actually entitled to. The excess is subtracted from your refund.15Internal Revenue Service. Instructions for Form 8962
For 2026 returns, there is no cap on the amount of excess advance credits you have to pay back. The income-based repayment limits that used to protect lower-income filers expired after 2025, so starting with the 2026 tax year you owe the full difference.16IRS.gov. Updates to Questions and Answers About the Premium Tax Credit A raise or a new job during the year, if you did not update the Marketplace, can produce a large repayment now.
When the Debt Belongs to Your Spouse
If you filed jointly and your refund was reduced to pay a debt that belongs only to your spouse — their past-due child support, their defaulted student loan, their old tax balance — you can ask for your share back through an injured spouse allocation. This is different from innocent spouse relief, which is about tax that was understated on a joint return. Injured spouse relief is specifically for when a joint refund was offset for one spouse’s individual debt.17IRS.gov. Innocent Spouse Relief and Injured Spouse Relief
File Form 8379 to claim your portion. You can attach it to the joint return or submit it on its own after the offset notice arrives. Expect about 11 weeks of processing if you e-file it with your return, and about 14 weeks on paper.18Internal Revenue Service. Instructions for Form 8379 If you already know an offset is coming, filing Form 8379 with the original return avoids the wait for reallocation later.
Identity Theft
Occasionally a shrunken or missing refund traces back to someone else filing a return under your Social Security number. This often shows up when e-filing is rejected because a return has already been filed in your name, but it can also produce an adjusted refund when the stolen filing creates conflicting records.
To resolve it, file a paper return with Form 14039 (Identity Theft Affidavit) attached, or submit Form 14039 electronically and mail the paper return separately.19Internal Revenue Service. How IRS ID Theft Victim Assistance Works These cases have taken an average of roughly 22 months to resolve, and your refund is held during that time. Do not send duplicate copies of Form 14039 or call repeatedly, as either can slow the case further.
What to Do Next
Match your response to your notice. For a CP11 or CP12 correction you agree with, do nothing; the IRS will issue the adjusted refund or bill you for any balance. If you disagree, call the number on the notice or mail a written response before the 60-day deadline printed on it.1Internal Revenue Service. Understanding Your CP12 Notice
For a CP49 that applied your refund to an old tax balance, call the IRS to confirm the debt and set up payment terms for anything still owed.3Internal Revenue Service. Understanding Your CP49 Notice For a Treasury Offset Program letter, call 800-304-3107 to identify the agency, then take up the dispute or repayment with that agency.7Bureau of the Fiscal Service. Treasury Offset Program – Contact Us
If the reduction is causing serious financial hardship, or if 30 days have gone by without progress through normal channels, the Taxpayer Advocate Service can step in. TAS is an independent office within the IRS that helps taxpayers facing economic harm or stalled cases.20Internal Revenue Service. Who May Use the Taxpayer Advocate Service Reach them at 877-777-4778 or through a local office.