How IRMAA works
IRMAA stands for income-related monthly adjustment amount. Most people pay the standard Part B premium of $202.90 a month in 2026. If your income is above the first bracket line, Social Security adds an amount to your Part B premium and a separate surcharge for Part D drug coverage. The Part D surcharge applies whether you have a standalone drug plan, a Medicare Advantage plan with drug coverage or a retiree plan with Part D, such as the HealthChoice Medicare supplement plans for Oklahoma public retirees, and it is paid to Medicare, not to the plan.
Three things surprise people:
- It looks back two years. Your 2026 premium uses your 2024 tax return. A big income year in your last year of work can raise your premium in your first years of retirement.
- The brackets are cliffs. Going one dollar over a line raises the premium for the whole year. It is not a tax on the dollars above the line.
- It is recalculated every year. If your income falls, your premium falls too, two years later or sooner if you file Form SSA-44.
What pushes Oklahoma retirees into a bracket?
IRMAA uses federal modified adjusted gross income: the adjusted gross income on your federal Form 1040 plus tax-exempt interest. Oklahoma has a state income tax, but your Oklahoma return isn't part of the calculation at all. These are the income sources that most often push Oklahoma retirees over a line:
- Public pensions. The taxable part of a pension counts in full on your federal return. That includes benefits from the Teachers' Retirement System of Oklahoma (OTRS) for retired school employees, the state retirement system for retired state employees, city and county plans, and police and firefighter plans. A couple with two public pensions can cross the joint line without much other income.
- Military retired pay and private pensions. Taxable retired pay, including from service at Tinker, Fort Sill, Vance or Altus, and private pension payments count the same way.
- Required minimum distributions. Withdrawals from traditional IRAs, 401(k)s and 403(b) or 457 plans are taxable income, and they grow as you age.
- Roth conversions. The converted amount counts in the year you convert. Spreading conversions over several years can keep you under a line.
- Selling land, minerals, a farm or a home. Capital gains above the home-sale exclusion count, and so do lease bonuses and royalties from oil and gas interests. A one-time sale of family land, a ranch or mineral rights can raise your premiums two years later.
- Taxable Social Security. The taxable part of your benefit is included in federal adjusted gross income, however your Oklahoma return treats it.
Tip: If you are 70½ or older and give to charity, a qualified charitable distribution sent straight from your IRA to the charity can count toward your required minimum distribution without being added to your adjusted gross income. The 2026 limit is $111,000 per person. Ask a tax professional whether it fits your situation.
What are the 2026 IRMAA brackets?
Income is 2024 MAGI. The Part B amount is the full monthly premium; the Part D amount is added to whatever your drug plan charges.
| Single (and head of household) | Married filing jointly | Part B premium | Part D surcharge |
|---|---|---|---|
| $109,000 or less | $218,000 or less | $202.90 | $0 |
| $109,001 to $137,000 | $218,001 to $274,000 | $284.10 | +$14.50 |
| $137,001 to $171,000 | $274,001 to $342,000 | $405.80 | +$37.50 |
| $171,001 to $205,000 | $342,001 to $410,000 | $527.50 | +$60.40 |
| $205,001 to $499,999 | $410,001 to $749,999 | $649.20 | +$83.30 |
| $500,000 or more | $750,000 or more | $689.90 | +$91.00 |
If you are married, lived with your spouse at any time in 2024 and filed separately, the brackets are different: $109,000 or less pays the standard premium, $109,001 to $390,999 pays $649.20 (Part D +$83.30), and $391,000 or more pays $689.90 (Part D +$91.00). The calculator handles this when you pick "Married filing separately". The 2027 brackets, based on 2025 income, aren't published yet; see Medicare costs in 2027.
Does IRMAA apply with HealthChoice or OTRS retiree coverage?
Yes. Your Part B premium, including any IRMAA, is billed by Social Security, not by EGID or OTRS. The HealthChoice Medicare supplement plans that the Employees Group Insurance Division (EGID), part of the Oklahoma Health Care Authority (OHCA) since July 2024, offers former state, education and local government employees include Part D drug coverage, so the Part D surcharge applies to members whose income is over a line. EGID's 2027 application says you need Part A to join a HealthChoice Medicare supplement plan and that the plan pays as if you have Part B, so most retirees keep Part B. OTRS pays a monthly premium supplement toward the health insurance of eligible retirees with at least ten years of service; it doesn't cover IRMAA. See state and teacher retirees and Medicare.
How do I ask Social Security to use newer income?
If your income has dropped because of a life-changing event, you can ask Social Security for a new decision with Form SSA-44. The events Social Security accepts are marriage, divorce or annulment, death of a spouse, work stoppage, work reduction, loss of income-producing property, loss of pension income, and an employer settlement payment. Retiring from a school district, a state agency, a tribal government or any other job counts as a work stoppage, which is the most common reason retirees file.
- Fill out Form SSA-44. List the event, its date, and your estimated income for the year.
- Attach proof. For example, a letter from your employer showing your last day of work, or a death certificate.
- Send it to Social Security. Mail it or bring it to a local Social Security office. If Social Security agrees, it recalculates your premium from your newer income.
If you disagree with the income Social Security used, for example because the IRS data was wrong or you amended your return, you can also ask for a reconsideration. More on premiums and the rest of 2026's amounts is on Medicare costs in 2026 and Medicare Part B. If you're still working, see working past 65. For questions about plan choices at your income, you can request a call from a licensed insurance agent.
Sources
- CMS — 2026 Medicare Parts A & B premiums and deductibles (IRMAA tables)
- Social Security — Premiums: rules for higher-income beneficiaries
- Social Security POMS HI 01101.010 — Modified adjusted gross income and the tax year used
- Social Security — Form SSA-44, Medicare income-related monthly adjustment amount, life-changing event (PDF)
- IRS — Retirement plan and IRA required minimum distributions FAQs (qualified charitable distributions)
- Employees Group Insurance Division (EGID, Oklahoma Health Care Authority) — Medicare options for retirees
- EGID — 2027 HealthChoice Medicare supplement application (Part A and Part B requirements) (PDF)
- Teachers' Retirement System of Oklahoma — Retiree health insurance (premium supplement)
Frequently asked questions
Which year's income sets my 2026 IRMAA?
Social Security uses the modified adjusted gross income (MAGI) on your 2024 federal tax return, the most recent one the IRS gives it. MAGI is your adjusted gross income plus any tax-exempt interest. If the 2024 return isn't available, Social Security may use 2023 and update it later.
Does my OTRS or state pension count toward IRMAA?
Yes, the taxable part of a pension counts, whether it comes from the Teachers' Retirement System of Oklahoma (OTRS), the state's public employees retirement system, a city or county plan, the military or a private employer. So do required minimum distributions, Roth conversions, capital gains and taxable Social Security.
Oklahoma doesn't tax all of my retirement income. Does that lower my IRMAA?
No. IRMAA is based only on your federal tax return. Oklahoma deductions, exclusions or exemptions on your state return don't change your federal MAGI, so they don't lower your Medicare premiums.
What if I just retired and my income dropped?
Retirement counts as a work stoppage, one of the life-changing events that let you ask Social Security to use a newer, lower income year. You file Form SSA-44 with proof of the event and an estimate of your current income.
Is IRMAA a sliding scale?
No. The brackets are cliffs: one dollar over a bracket line moves you to the next premium for the whole year. That is why the calculator shows how far over the line you are.
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