The medical expense deduction allows you to deduct only qualifying, unreimbursed medical and dental expenses above an adjusted gross income threshold—and only if you itemize. For tax year 2025, that floor is 7.5% of AGI. Subtract reimbursements first, calculate the floor, and deduct only the excess—not your entire medical bill. The IRS Schedule A instructions confirm this calculation for tax year 2025.
How do you calculate the medical expense deduction?
For tax year 2025, the federal calculation is:
[
D=\max(0,\ E-0.075\times A)
]
Where:
- (D) is the medical expense amount deductible on Schedule A, in dollars.
- (E) is qualifying medical and dental expenses paid during tax year 2025, after reimbursements and exclusions, in dollars.
- (A) is AGI for tax year 2025, in dollars.
If qualifying unreimbursed expenses equal or fall below the floor, the medical deduction is zero. If they exceed it, only the excess qualifies. The floor is a subtraction from eligible expenses, not a tax rate applied to your medical spending.
Use the same tax year for your expenses, reimbursements, and AGI. For a different tax year, obtain the applicable percentage and reporting instructions from that year's Schedule A instructions rather than assuming an earlier year's figures apply.
Use AGI—not wages, MAGI, or taxable income
For tax year 2025, the Schedule A instructions direct you to AGI on Form 1040 or Form 1040-SR, line 11b. Do not substitute gross salary, take-home pay, taxable income after deductions, or a modified adjusted gross income figure used for another tax provision.
The medical deduction does not reduce the AGI used to calculate its own floor. It enters Schedule A and, when you itemize, contributes to the deductions used to determine taxable income.
Which medical expenses count before applying the floor?
Start with qualifying expenses you actually paid during the tax year. A bill for treatment is not enough if it remains unpaid. For credit card payments, the IRS generally uses the year you charged the expense, not the year you paid the credit card balance. These timing rules appear in Publication 502, Medical and Dental Expenses.
Common qualifying expenses include payments for medical and dental treatment, prescription medicines and insulin, medically necessary eyeglasses, hearing aids, and eligible health insurance premiums paid with after-tax money. Expenses merely beneficial to general health do not automatically qualify. Nonprescription medicines other than insulin generally do not qualify for this Schedule A deduction, even when a tax-favored health account may treat them differently.
You can generally include qualifying expenses paid for yourself, your spouse, and eligible dependents. Medical-expense dependency rules include exceptions, so neither “I paid a relative's bill” nor “I did not claim this person as a dependent” settles eligibility by itself. Check Publication 502's “Whose Medical Expenses Can You Include?” section before adding another person's expenses.
Some categories require additional calculations. Qualified long-term care insurance premiums, medical transportation, and certain home improvements have their own restrictions or limits. Establish the qualifying amount under the applicable tax-year rules before applying the AGI floor.
How do reimbursements and tax-free payments affect the deduction?
Subtract insurance payments and other reimbursements attributable to the expenses before calculating the deductible excess. If insurance paid the provider directly and you paid only the remaining balance, begin with your own qualifying payment—not the provider's total charge. Do not subtract the insurer's payment again from a balance that already excludes it.
Also exclude expenses paid or reimbursed through tax-free arrangements, including qualifying HSA distributions and health FSA reimbursements. Pretax payroll-paid health insurance premiums do not become deductible again on Schedule A. Likewise, premiums deducted through the self-employed health insurance deduction cannot also be deducted as medical expenses.
Marketplace insurance requires coordination with the premium tax credit. The Schedule A instructions say to complete Form 8962 first when advance credit payments were made or you may qualify for the credit; your premium deduction cannot simply equal the policy's full premium.
A later reimbursement belongs to a separate calculation
A reimbursement received for expenses deducted in an earlier year does not automatically reduce the current year's medical expense total. Instead, some or all may have to be included in income to the extent the earlier deduction produced a tax benefit. Publication 502 explains how to determine the includible amount.
Worked example: expenses above the AGI floor
Assume a single taxpayer is preparing a tax year 2025 federal return with these hypothetical facts:
| Input | Hypothetical tax year 2025 amount |
|---|---|
| AGI | $100,000 |
| Qualifying medical and dental expenses paid before reimbursement | $14,000 |
| Same-year insurance reimbursement for those expenses | $2,000 |
| Expenses paid through tax-free health accounts | $0 |
| Applicable medical expense floor | 7.5% of AGI |
Assume all expenses meet the qualification and payment requirements, and none has been deducted elsewhere. The tax year 2025 floor comes from the Schedule A instructions.
Step 1: Subtract the reimbursement
[
E=14{,}000-2{,}000=12{,}000
]
The taxpayer has $12,000 of qualifying unreimbursed expenses.
Step 2: Calculate the AGI floor
[
F=100{,}000\times0.075=7{,}500
]
The first $7,500 of qualifying unreimbursed expenses does not produce a medical deduction.
Step 3: Calculate the deductible excess
[
D=\max(0,\ 12{,}000-7{,}500)=4{,}500
]
The medical expense amount available for Schedule A is $4,500—not $14,000 or $12,000. That amount can contribute to an itemized deduction total; it is not a $4,500 tax credit, tax saving, or refund.
All example amounts are whole dollars, so rounding does not change the result. When preparing a return with cents, follow the Form 1040 rounding instructions: if you elect whole-dollar rounding, apply it consistently, drop amounts below 50 cents, and round amounts from 50 through 99 cents up. When combining amounts for one line, add the underlying amounts including cents and round the total—not each receipt separately.
Does exceeding the floor mean you should itemize?
Not necessarily. The medical floor determines how much enters the medical deduction category. Whether itemizing helps depends on your total allowable itemized deductions compared with the standard deduction available for your tax year and filing status. You generally cannot take the standard deduction and add the Schedule A medical deduction on top of it.
In the example, $4,500 of deductible medical expenses alone does not establish that itemizing is preferable. Add other allowable Schedule A deductions after their respective limits, then compare the resulting total with your available standard deduction.
See Standard Deduction vs. Itemized: Which Should You Use? for the broader comparison.
Filing status matters even though the medical floor calculation uses AGI. A joint return uses the couple's joint AGI and eligible expenses. Separate returns require attention to who actually paid the expenses and, where applicable, community property rules. A married-filing-separately taxpayer generally cannot claim the standard deduction if the spouse itemizes.
How should you enter expenses in the calculator?
The Medical Expense Deduction Calculator subtracts its reimbursement input from its expense input, then subtracts the AGI floor. Its current expense field is labeled “Unreimbursed medical expenses,” but the displayed formula subtracts reimbursements again. Avoid counting the same reimbursement twice.
Use one consistent input method:
| Your records contain | Expense field | Reimbursement field |
|---|---|---|
| Qualifying expenses before reimbursement | Enter the qualifying pre-reimbursement amount | Enter the corresponding reimbursement |
| Qualifying expenses already net of reimbursement | Enter the net qualifying amount | Enter $0 for reimbursements already removed |
For the hypothetical example, enter either $14,000 and $2,000, or $12,000 and $0. Both approaches produce the same net expense amount under the displayed formula. Do not enter $12,000 and $2,000, because that subtracts the reimbursement twice.
Enter your tax year's AGI and verify the floor percentage against the applicable IRS instructions. The tool accepts an editable percentage; it does not independently determine the correct tax-year rule or whether a payment qualifies.
Why can estimated tax savings differ from the actual tax result?
The calculator's “Estimated tax savings” output multiplies the medical deduction by the marginal tax rate you enter. That is a simplified estimate, not a comparison of completed federal returns. It does not determine whether itemizing beats the standard deduction or how much additional deduction the medical expenses actually create.
A marginal rate applies to an additional portion of taxable income; an effective rate describes an average tax burden. Neither substitutes for calculating the return under the relevant alternatives. Final federal income tax may require the Tax Table, Tax Computation Worksheet, or a special worksheet specified in the applicable Form 1040 instructions.
Payroll withholding is a payment toward tax, not the final liability, and claiming a deduction does not itself change the amount withheld from your paycheck. The calculator also does not establish a state deduction or submit a return or election. Use its result to compare supplied facts, retain payment and reimbursement records, and verify the deduction against the official instructions before filing.