Form 1040 Schedule A is used to list itemized tax deductions instead of claiming the standard deduction. Tax filers can use this form when qualifying deductible expenses such as mortgage interest, medical expenses, state and local taxes, and/or charitable contributions. These expenses must exceed the standard deduction amount for the taxpayer’s filing status.
Who Should File Schedule A?
If your eligible expenses are larger than the standard deduction for your tax filing status, it makes sense to file your taxes with Schedule A. You can lower your taxable income through itemizing deductions, but if your expenses are less than the standard deduction given to you by the IRS, there’s no point to itemizing.
Common expenses that may allow you to file Schedule A include:
- Unreimbursed medical and dental expenses (especially if they exceed 7.5% of your AGI)
- Home mortgage interest on a primary residence and/or a secondary residence
- Substantial donations (cash or property) to nonprofit organizations
- Large payments in taxes to state and local governments. This includes property taxes and income taxes to a state (up to the current SALT cap)
- Loss of property due to theft or natural disaster (only if the disaster was federally recognized)
- Notable interest expenses on loans that are given for the use of investments
Homeowners, taxpayers with significant medical expenses, and those who are very charitable may quickly fall into these categories, allowing for even greater deductions than the standard deduction.
2025 Standard Deduction Amounts (Estimated)
| Filing Status | Standard Deduction |
| Single | ~$14,900 |
| Married Filing Jointly | ~$29,800 |
| Head of Household | ~$22,200 |
Deciding whether to itemize your deductions should depend on how much your deductible expenses are in relation to your standard deduction. If your standard deduction is considerably larger, then that is generally going to be the better option, as there is less paperwork to fill out with smaller deductions.
Your tax returns will most likely become easier to do if you have a home, large medical expenses, and consistently do big donations because you will be itemizing more easily in all those cases. For others, especially those that do not have mortgage interest, the standard deduction tends to be the better and easier option.
How Do You Complete Schedule A? (Line-by-Line Instructions)
Below is a clear step-by-step process for each section of Schedule A:
Step 1 — Medical and Dental Expenses
You may deduct qualified medical expenses that exceed 7.5% of your AGI.
Instructions:
- Add eligible medical expenses (doctor visits, surgery, prescriptions, dental care, etc.).
- Enter total on Line 1.
- Calculate 7.5% of your AGI (Line 2).
- Subtract Line 2 from Line 1 (Line 4).
- Only the amount above the 7.5% threshold is deductible.
Example:
AGI: $80,000 of 7.5% is $6,000
Medical expenses: $10,000
Deductible: $4,000
Step 2 — Taxes You Paid (SALT Deduction)
You can deduct up to $10,000 total of state/local taxes.
Includes:
- State or local income tax
- Sales tax (optional instead of income tax)
- Property tax
- Personal property tax (e.g., vehicle registration based on value)
Enter amounts on Lines 5–7, but the total cannot exceed $10,000 ($5,000 if married filing separately).
Step 3 — Home Mortgage Interest and Points
You can deduct interest on mortgage debt up to $750,000 (post-2017 loans).
Steps:
- Enter mortgage interest from Form 1098 on Line 8a.
- Enter mortgage interest not reported on 1098 on Line 8b.
- If applicable, enter points on Line 8c.
- Include home equity loan interest only if used to improve your home.
Step 4 — Gifts to Charity
Cash contributions are generally deductible up to 60% of AGI.
What to enter:
- Cash donations (Line 11)
- Non-cash donations (Line 12)
- Vehicle donations (Line 13)
- Attach Form 8283 if non-cash donations exceed $500
Be sure to maintain receipts or acknowledgment letters.
Step 5 — Casualty and Theft Losses
Only losses from a federally declared disaster are deductible.
Report these on Line 15 and attach Form 4684.
Step 6 — Other Itemized Deductions
The IRS allows a limited set of additional deductions, including:
- Gambling losses (up to gambling winnings)
- Impairment-related work expenses
- Estate tax on income in respect of a decedent (IRD)
Enter these items on Line 16.
Step 7 — Add All Itemized Deductions
Add all applicable categories and enter the total on Line 17, then transfer this amount to Form 1040, Line 12a.
When Is Schedule A Due?
Schedule A will be due on Tax Day which is April 15, 2026, for the 2025 tax year. This form cannot be done by itself and has to be filed with your Form 1040. If you decide to itemize your deductions, Schedule A becomes part of your complete tax filing package.
If you need more time to prepare your return, you can request an automatic extension:
- You can file Form 4868 to extend your filing deadline to October 15, 2026.
- This is an extension of time to file, but it is not an extension of time to pay, which is important to remember.
- Any taxes you owe will still need to be paid by April 15, otherwise, you may incur late payment penalties and interest.
An extension can be beneficial if you need more time to gather receipts, documentation, and supporting records for your itemized deductions, especially if they are complex records like medical, mortgage, or charitable deductions.
Are There Penalties for Filing Schedule A Incorrectly?
Yes. If you claim an unreasonable or excessive deduction that lowers your taxes, that could result in IRS penalties. The IRS penalties for improper filing on Schedule A could result in the following consequences:
- A 20% accuracy-related penalty for the negligence or disregard of IRS rules.
- A penalty for a substantial understatement of tax, which occurs when the understatement of tax exceeds the greater of 10% of your tax liability, or $5,000.
- Disallowed deductions which leads the IRS to remove any unsupported expenses and send you a bill for the tax owed.
- Interest on any tax owed.
- Increased chances of being audited, especially if the deductions you claim are large in comparison to your income.
In order to protect yourself, you need to keep thorough and precise records, including, but not limited to, receipts, statements for mortgages, letters acknowledging charitable donations, medical invoices, tax documents, etc. This type of documentation is your best defense in the case of an IRS audit.
Need Help Filing Schedule A?
Incorrect itemized deductions are one of the top IRS audit triggers. If you’re unsure whether to itemize—or how to file correctly—our team can help. Contact us today for professional support.
Dimov Tax & CPA Services offers:
- Full Schedule A and Form 1040 preparation
- Audit-proof documentation review
- Tax planning for homeowner
Frequently Asked Questions (FAQ)
Is Schedule A required every year?
No. You only file Schedule A in years when itemizing deductions provides a greater tax benefit than taking the standard deduction.
Can I itemize if I take the standard deduction?
No. You must choose either the standard deduction or itemized deductions, you cannot use both in the same tax year. If the standard deduction is higher, itemizing won’t provide additional benefits.
Do homeowners usually itemize?
Often, yes. Homeowners are more likely to itemize because mortgage interest and property taxes can create substantial deductions that exceed the standard deduction.
Can I itemize if I’m self-employed?
Yes. Being self-employed does not prevent you from itemizing deductions. However, it’s important to separate expenses correctly: business expenses belong on Schedule C, while personal itemized deductions, such as mortgage interest, medical bills, or charitable donations, go on Schedule A. The two forms serve different purposes and should not be mixed.
Does Schedule A affect my state tax return?
In many states, yes. Several states allow taxpayers to itemize deductions or follow rules similar to the IRS. If your state permits itemizing, your federal Schedule A amounts may flow into your state return. However, rules vary widely, some states cap deductions, modify them, or offer no itemized deductions at all.