502X: Maryland Amended Tax Form (2025)
Maryland · Comptroller of Maryland · Used for tax years 2025
Maryland Form 502X is the amended individual income tax return for 2025. It reports originally filed amounts, changes, and corrected amounts for income, deductions, exemptions, taxes, payments, and credits to calculate a refund or additional amount due.
Who files this form
Use the 2025 Maryland Form 502X to amend a previously filed Maryland income tax return, including changes to income, deductions, credits, filing status, or residency status.
Most changes to your federal return also affect your Maryland return. If the IRS makes a final adjustment that increases your Maryland taxable income, you must file Form 502X.
You must file electronically if you are claiming or changing business income tax credits from Form 500CR.
When it's due
The instructions print these dates for tax year 2025 estimated payments, not as a general Form 502X filing deadline:
- January 15, 2026: Fourth declaration payment date.
- January 31, 2026: Instead of making that fourth payment, you may file a return and pay the balance due by this date.
What you'll need
Have your original Maryland return, or your previously adjusted amounts, and your federal return available. Attach the documents that apply to your changes:
- Federal amendment: A copy of Form 1040X and revised schedules.
- IRS corrections: A copy of the IRS notice.
- Additional Maryland withholding: Forms W-2 and 1099 attached to the front of the return.
- Estimated payments not credited: Copies of cancelled checks or money orders.
- Dependent changes: Amended Form 502B.
- Credit changes: Corrected Form 502CR, Form 502S, other state returns, and required documentation or certification, as applicable.
- Income changes: Revised Form 502SU or other corrected forms required for the items changed.
- Net capital gain subject to additional tax: Form 502CG.
- Net operating loss claim: Copies of the federal loss-year return and Form 1045, Schedules A and B.
- Estimated-tax interest changes: Completed or revised Form 502UP, as applicable.
Attach other required forms, K-1s, schedules, and statements. Do not attach worksheets.
How to file
- Complete your federal amendment first, if applicable. Print the Maryland form using blue or black ink.
- Complete page 3 first. Enter original or previously adjusted amounts in Column A, changes in Column B, and corrected amounts in Column C. Complete Part II if you itemized deductions.
- Explain each change in Part III on page 4. Include the affected page 2 line number and the reason for the change.
- Complete the tax and payment calculations. Sign and date page 4. Both spouses must sign a joint return. A paid preparer must also sign and enter their PTIN.
- Attach the required supporting documents.
Mail your return to:
Comptroller of Maryland
Revenue Administration Division
Amended Return Unit
110 Carroll Street
Annapolis, MD 21411-0001
For private delivery services, use:
Comptroller of Maryland
Revenue Administration Division
110 Carroll Street
Annapolis, MD 21411-0001
Electronic filing is required to claim or modify business income tax credits from Form 500CR.
If you owe tax: Pay in full with the return. Make your check or money order payable to “Comptroller of Maryland” and attach it to the front. Write the last four digits of your Social Security number or ITIN, the tax year, and the tax type on the payment in blue or black ink. Do not send cash. The form also provides a QR code for online payment.
Common mistakes
- Filing before the original return is processed. For current-year returns, allow at least six weeks.
- Choosing a political subdivision by ZIP Code alone. Use the printed subdivision list and your actual residence. Do not enter a PO Box as your Maryland physical address.
- Leaving changes unexplained. Explain each change in Part III and attach required supporting forms and schedules.
- Including interest or penalties on line 24. This line is for tax paid, not interest or penalties.
- Missing signatures. Both spouses must sign a joint return. A change to or from married filing jointly also requires both signatures.
- Leaving identifying details off a payment. Missing the last four digits of your Social Security number or ITIN, tax year, or tax type will delay payment processing.
- Expecting certified mail to speed up handling. The instructions say it does not provide special handling and may delay your refund.
Questions people ask
Do I have to itemize in Maryland if I itemized on my federal return?
No. The instructions say you may use either Maryland deduction method. Figure your tax both ways to determine which is better for you.
What if my income amounts have not changed?
In Part I, check the no-changes box, complete Column A, and enter the total on line 17 of Column C.
Can I change from married filing jointly to married filing separately?
Generally, you cannot make that change after the original return due date. Any change to or from married filing jointly requires both spouses’ signatures and a full explanation in Part III.
Will Maryland issue a very small refund?
No refund of less than $1.00 will be issued.
Will I owe interest if the amendment shows additional tax due?
Interest must be calculated and paid on a tax balance due. It runs from the original return due date until the tax is paid.