Since it was paid in 2025 then it is a valid medical expense to be entered as an itemized deduction on the 2025 Schedule A. There is no need to designate this payment as for 2026 Medicare premium.
Health care insurance premiums, including dental and vision insurance premiums, and other medical expenses that you paid with out of pocket funds and were not reimbursed are an eligible medical expense that you can deduct using Schedule A for itemized deductions. However, only your total medical expenses that are greater than 7.5% of your Adjusted Gross Income (AGI) can be deducted. Your total itemized deductions reported on Form 1040 Schedule A must be greater than the standard deduction for your filing status to have any tax benefit.
Standard deductions for 2025
Single - $15.750 add $2,000 if age 65 or older
Married Filing Separately - $15,750 add $1,600 if age 65 or older
Married Filing Jointly - $31,500 add $1,600 for each spouse age 65 or older
Head of Household - $23,625 add $2,000 if age 65 or older
To enter your medical expenses -
Click on Federal Taxes (Personal using Home and Business)
Click on Deductions and Credits
Click on I'll choose what I work on (if shown)
Scroll down to Medical
On Medical Expenses, click the start or update button
