Form SSA-1099-SM is the Social Security Benefit Statement the Social Security Administration mails each January to everyone who received benefits during the prior year. The “SM” stands for “self mailer” and refers to how the document is folded and sealed for delivery, not to any Medicare-specific variant. The form reports your gross benefits, any amounts you repaid, your net benefits, and an itemized list of what was withheld from your checks, including Medicare premiums. You use it to prepare your federal tax return.
What “SM” Means and Why Yours May Look Different
The SSA produces several versions of the SSA-1099 to handle different mailing and language situations: domestic English, Spanish, foreign, updated, and corrected editions. The self-mailer versions carry the “SM” suffix. The data inside is the same regardless of which version arrives.1Social Security Administration. POMS GN 05002.005 – The Social Security Benefit Statement
One boundary worth noting: if you’re a nonresident alien for tax purposes, the SSA sends Form SSA-1042S instead, which applies different withholding rules.2Social Security Administration. Nonresident Alien Tax Withholding
How to Read the Boxes
Box 3 shows the total gross benefits the SSA paid on your behalf during the year, before any deductions. Directly beneath that figure, in the “Description of Amount in Box 3” area, the form lists each withholding that was applied. Medicare Part B, Part C, and Part D premiums appear as separate line items here.3Social Security Administration. POMS GN 05002.010 – Social Security Benefit Statement – Box 3, Benefits Paid
Other items that can show up in the same area include voluntary federal income tax withholding, overpayment recoveries, attorney fees, garnishments, and Treasury offsets. Added together, they explain the gap between what the SSA paid on your behalf and what actually landed in your bank account.3Social Security Administration. POMS GN 05002.010 – Social Security Benefit Statement – Box 3, Benefits Paid
Box 4 reports any benefits you repaid to the SSA during the year. Box 5 equals Box 3 minus Box 4 and represents your net benefits. The Box 5 figure is the one that drives your tax calculation.4Social Security Administration. POMS GN 05002.014 – Social Security Statement – Box 5, Net Benefits
If you’re subject to the Income-Related Monthly Adjustment Amount (IRMAA), the higher premium total is already baked into the Medicare line items. Don’t try to recalculate your annual premium by multiplying a monthly amount by twelve. Mid-year rate changes, late enrollment penalties, and IRMAA adjustments all can throw that math off. Use the exact figure printed on the form.
Figuring Out Whether Your Benefits Are Taxable
Whether any of your Social Security income is taxable depends on your “provisional income,” which is roughly half the Box 5 amount plus all your other income. The IRS compares that total against base amounts that haven’t changed in decades.5Internal Revenue Service. Publication 915 – Social Security and Equivalent Railroad Retirement Benefits
For single filers:
- Below $25,000: benefits are not taxable
- $25,000 to $34,000: up to 50% of benefits may be taxable
- Above $34,000: up to 85% of benefits may be taxable
For married couples filing jointly:
- Below $32,000: benefits are not taxable
- $32,000 to $44,000: up to 50% of benefits may be taxable
- Above $44,000: up to 85% of benefits may be taxable
Because these thresholds aren’t indexed for inflation, most retirees with even modest additional income from pensions, retirement account withdrawals, or investments end up owing federal tax on part of their benefits.6Internal Revenue Service. IRS Reminds Taxpayers Their Social Security Benefits May Be Taxable
If you received more than one SSA-1099 during the year, add the Box 5 amounts from each form. Report the combined total on line 6a of Form 1040 and the taxable portion on line 6b. Publication 915 includes a worksheet that walks you through the calculation.5Internal Revenue Service. Publication 915 – Social Security and Equivalent Railroad Retirement Benefits
Using the Medicare Premium Total on Schedule A
The Medicare premium figure on your SSA-1099 does a second job at tax time: it’s a deductible medical expense if you itemize on Schedule A. Part B and Part D premiums both qualify, including any IRMAA surcharges, and you can combine them with other out-of-pocket medical costs.7Internal Revenue Service. Publication 502 – Medical and Dental Expenses
Only the portion of medical expenses that exceeds 7.5% of your adjusted gross income counts toward the deduction. For someone with an AGI of $50,000, the first $3,750 in medical costs produces no tax benefit. Only amounts above that floor reduce taxable income.7Internal Revenue Service. Publication 502 – Medical and Dental Expenses
Itemizing only helps if your total deductions exceed the standard deduction. The 2026 standard deduction is $16,100 for single filers and $32,200 for married couples filing jointly, with an additional $2,050 (single) or $1,650 per spouse (married) for taxpayers 65 and older. For retirees with heavy medical bills, the Medicare premium total on the SSA-1099 is often the single largest line in a viable Schedule A deduction. For everyone else, the standard deduction usually wins.
Replacing or Correcting Your Form
The SSA mails benefit statements between early January and January 31. Replacement forms become available online starting February 1.1Social Security Administration. POMS GN 05002.005 – The Social Security Benefit Statement If yours hasn’t arrived or you’ve misplaced it, you have three ways to get a replacement:
- Online is fastest. Sign in to your my Social Security account at ssa.gov, select “Replace Your Tax Form SSA-1099/SSA-1042S,” choose the year, and download it. Replacements go back six years.8Social Security Administration. How Can I Get a Replacement Form SSA-1099/1042S, Social Security Benefit Statement
- By phone, call 1-800-772-1213 (TTY 1-800-325-0778), Monday through Friday, 8:00 a.m. to 7:00 p.m. A paper copy will be mailed to the address on file.8Social Security Administration. How Can I Get a Replacement Form SSA-1099/1042S, Social Security Benefit Statement
- In person, visit a local Social Security office to request a printed copy.
If you think the amounts are wrong, contact the SSA through the same channels and ask for a review. If the agency agrees, it will issue a corrected statement designated SSA-1099-SM-C. File or amend your return using only the corrected form.1Social Security Administration. POMS GN 05002.005 – The Social Security Benefit Statement
One wrinkle: when a beneficiary’s monthly benefit is smaller than their Part B premium, the SSA makes manual adjustments so the premium amount shows up correctly in Box 3. Those corrections are generally completed by February 28, so a form received in early January may not yet reflect the final figures in that situation.1Social Security Administration. POMS GN 05002.005 – The Social Security Benefit Statement