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CP28 notice: what it means and what to do
Got an IRS CP28 notice? Here is what it means, your deadline, what to check before you answer, and how to reply. Check your own letter free: it stays on your phone.
Check my CP28 notice freeWhat the IRS says this notice is about
You claimed a Home Mortgage Interest Deduction on Schedule A of your 2024 Form 1040 tax return. The amount of interest you may deduct is limited by your mortgage size (outstanding mortgage amount) and date (mortgage origination date). Our records show the amount of interest that you claimed exceeds the limit. This notice has been sent to inform you of this issue and to help you verify the amount of your Home Mortgage Interest Deduction.
What you need to do
Review your Schedule A, Form 1040 federal tax return for the year listed in the notice. Find important information about the Home Mortgage Interest Deduction . Verify the amount of your claim. If you claimed this deduction incorrectly:
- File an amended return . If you filed electronically, you may file your amended return electronically. You can get help at an IRS Taxpayer Assistance Center .
- Share your CP28 letter with anyone who helped you prepare your return.
- Verify future returns for eligibility prior to claiming the deduction.
Failure to review and address any incorrect information could result in additional action from the IRS.
Your deadline
Answer by the date printed on your notice. If there is no date, answer as soon as you can, and call the number on the notice if you need more time.
What to check before you answer
Is this letter really from the IRS?
The IRS writes first by mail. A real letter shows a notice or letter number, your name and part of your tax ID number. The IRS does not ask for payment by gift card, crypto or wire transfer. If in doubt, sign in to your IRS online account, where many notices are listed.
Common questions
What is the Home Mortgage Interest Deduction? (added Sept. 30, 2025)
A tax deduction for qualified homeowners to deduct home mortgage interest, primarily limited by your qualifying home(s), the mortgage size (outstanding mortgage amount), and date (mortgage origination date).
How much can I deduct? (added Sept. 30, 2025)
The amount of your Home Mortgage Interest Deduction depends on the following:
- Mortgage Date (Mortgage Origination Date) Review when you incurred your home mortgage. Your loan origination date sets a limit on the amount of interest you may deduct.
- Mortgage Size (Outstanding Mortgage Amount) Review the total amount of your debt. Example: On or after December 16, 2017, you may deduct mortgage interest on a mortgage up to $750,000 (Single filers) or $375,000 (Married filing separate filers). If your mortgage debt exceeds this limit, you may only deduct mortgage interest up to the limit. Other limitations may apply. For all requirements and limitations, see Publication 936, Home Mortgage Interest Deduction .
What properties qualify for this deduction? (added Sept. 30, 2025)
This interest deduction applies to mortgages secured by your main and second qualified home: a house, condominium, cooperative, mobile home, house trailer, boat, or similar property that has sleeping, cooking, and toilet facilities.
Special situations, such as rentals, divided use of the home, business use of the home, homes under construction, and time-sharing, may affect your deduction.
What if I have multiple properties? (added Sept. 30, 2025)
You may claim a mortgage interest deduction for up to two homes: a main and a second qualified home.
- Your main home is the home where you ordinarily live most of the time.
- Your second home is a home that you use as your second home. If you have more than one second home, you can treat only one as the qualified second home. If you rent it out part of the year, you must also use it as a home during the year for it to be a qualified home. You must use this home for more than 14 days or 10% of the days the home was used as a rental, whichever is longer.
- If you don't meet this requirement, the home is considered rental property and not a second home.
A mortgage interest deduction on two properties may look like this:
Dana has a $250,000 mortgage on her main home and $700,000 mortgage on her second home dated after 2020. Her mortgage interest deduction is limited to $750,000 of mortgage debt (married filing jointly).
- Together, she has $950,000 of total mortgage debt. This amount is greater than the dollar limit for her date range ($750,000).
- Dana may deduct interest on up to $750,000 of the mortgages.
What if my qualifying main home and second home have different mortgage dates? (added Sept. 30, 2025)
You must calculate the amount of home mortgage interest you may deduct. To calculate your home mortgage interest deduction, use Table 1. Worksheet To Figure Your Qualified Loan Limit and Deductible Home Mortgage Interest for the Current Year in Publication 936, Home Mortgage Interest Deduction .
Helpful information
Follow the links below to read more about the home mortgage interest deduction and related topics.
- Publication 936, Home Mortgage Interest Deduction
- Publication 530, Tax Information for Homeowners
Follow the links below to read more about filing an amended return.
- Form 1040-X Frequently asked questions
- Video: Amending a Return
- Make a payment
- Get help with tax debt
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