The rules behind the number.
A self-contained reference for Medicare IRMAA, the 2026 published tables, filing-status mapping, tax-form lines, and the limits of the calculation. Primary sources are linked for verification.
IRMAA in plain language
What it is
An income-related monthly adjustment added to Part B and Part D premiums. It is not a separate plan, a tax, or a penalty for a one-time event by itself.
Which income year
Ordinarily the tax return from two years before the premium year. For 2026 premiums, normally the 2024 return; 2023 may be used when 2024 is unavailable.
Which income measure
Federal AGI plus tax-exempt interest. This is not taxable income, ACA Marketplace MAGI, or Roth-eligibility MAGI.
Who is assessed
Each Medicare beneficiary separately, even when a joint return supplies the household MAGI. The household total is a sum of individual assessments.
2024 Form 1040: line 11 + line 2a. The 2025 form uses lines 11a and 11b for AGI, a mapping difference the calculator displays but does not use for a live 2027 calculation because no official 2027 pack is bundled.
2026 official Part B and Part D amounts
Standard Part B premium: $202.90 per month. Part D national base beneficiary premium: $38.99 — a benchmark, not every plan's premium.
| 2024 MAGI — single | 2024 MAGI — joint | Part B surcharge | Part B total | Part D IRMAA |
|---|---|---|---|---|
| Up to $109,000 | Up to $218,000 | $0.00 | $202.90 | $0.00 |
| More than $109,000 and up to $137,000 | More than $218,000 and up to $274,000 | $81.20 | $284.10 | $14.50 |
| More than $137,000 and up to $171,000 | More than $274,000 and up to $342,000 | $202.90 | $405.80 | $37.50 |
| More than $171,000 and up to $205,000 | More than $342,000 and up to $410,000 | $324.60 | $527.50 | $60.40 |
| More than $205,000 but below $500,000 | More than $410,000 but below $750,000 | $446.30 | $649.20 | $83.30 |
| $500,000 or more | $750,000 or more | $487.00 | $689.90 | $91.00 |
Married filing separately — accelerated schedule
This schedule is used when MFS spouses lived together at any point during the tax year. SSA generally assumes that until an attestation establishes living apart for the entire year.
| 2024 individual MAGI | Part B total / mo | Part D IRMAA / mo |
|---|---|---|
| Up to $109,000 | $202.90 | $0.00 |
| More than $109,000 but below $391,000 | $649.20 | $83.30 |
| $391,000 or more | $689.90 | $91.00 |
Source: CMS 2026 Medicare Parts A & B fact sheet (opens in a new tab), corroborated by SSA POMS HI 01101.020 (opens in a new tab). Part D benchmark source: CMS 2026 Part D bid information (opens in a new tab).
Five federal filing statuses, three Medicare schedules
| Federal filing status | Medicare schedule | Required handling |
|---|---|---|
| Single | Individual | No special question. |
| Head of household | Individual | Mapped to the individual table for Medicare purposes. |
| Qualifying surviving spouse | Individual | Mapped to the individual table; the tax-law qualification still controls the filing status. |
| Married filing jointly | Joint | Each enrolled spouse is assessed separately against the joint MAGI. |
| Married filing separately — lived together at any point | Accelerated MFS | Uses published surcharge levels 4 and 5 above the first threshold. |
| Married filing separately — lived apart all year | Individual, subject to SSA attestation | SSA applies the individual table only after accepting an attestation; only the attesting spouse is adjusted. |
Where to find the two numbers
| Tax year | AGI line(s) | Tax-exempt interest | Status | Note |
|---|---|---|---|---|
| 2023 | 11 | 2a | Verified | Verified directly against the IRS 2023 Form 1040: AGI line 11 plus tax-exempt interest line 2a. |
| 2024 | 11 | 2a | Verified | SSA POMS HI 01101.010 identifies line 11 (AGI) and line 2a (tax-exempt interest) for the ordinary IRMAA MAGI calculation. |
| 2025 | 11a and 11b | 2a | Verified | Verified IRS 2025 form: AGI is line 11a, carried to 11b; capital gains 7a; standard/itemized deductions 12e; QBI 13a; Schedule 1-A deductions 13b. Below-AGI deductions do not reduce Medicare MAGI. A verified form mapping does not provide unbundled 2027 premium rates. |
Do not add wages, IRA distributions, or capital gains a second time if you already entered the AGI from a completed return. The calculator adds only tax-exempt interest to the AGI you enter.
Tax deductions and the correct year
The senior deduction does not lower IRMAA MAGI
The 2025 Schedule 1-A enhanced deduction for seniors is reported on Form 1040 line 13b, after AGI on lines 11a/11b. It reduces taxable income, not AGI, and does not reduce Medicare IRMAA MAGI. Do not subtract it, your standard deduction, or itemized deductions from the AGI entered here.
Verify the 2025 Form 1040 lines (opens in a new tab)
QCD limits follow the distribution tax year
A qualifying charitable distribution can exclude an otherwise taxable IRA amount from income. The cap belongs to the year of distribution, not the Medicare premium year. If your filed AGI already excludes a QCD, do not subtract it again.
| Distribution tax year | Annual QCD cap | Normal Medicare premium year | Official source |
|---|---|---|---|
| 2023 | $100,000 | 2025 | IRS notice (opens in a new tab) |
| 2024 | $105,000 | 2026 | IRS notice (opens in a new tab) |
| 2025 | $108,000 | 2027 — premium rates not bundled | IRS notice (opens in a new tab) |
| 2026 | $111,000 | 2028 — premium rates not bundled | IRS notice (opens in a new tab) |
QCDs generally require age 70½ at the time of distribution, a direct eligible IRA-to-charity transfer, otherwise taxable funds and appropriate substantiation. Deductible IRA contributions after age 70½ can reduce the excludable amount. The annual cap is not a promise that the full amount is available to you.
Frequently asked questions
16 questions and 16 glossary terms. Search runs in your browser.
Will the new senior deduction reduce my Medicare surcharge?
No. For 2025, the Schedule 1-A senior deduction appears below AGI on Form 1040 line 13b. Medicare MAGI is AGI plus tax-exempt interest. Do not deduct this amount from the AGI entered into the calculator.
Official source (opens in a new tab)Can I use this calculator for both spouses filing separately?
Yes. Select married filing separately, answer the tax-year living-arrangement question, and include your spouse in coverage. Enter their own AGI and tax-exempt interest. The household sum combines two independent assessments; incomes are never pooled. Each spouse must separately establish any lived-apart request with SSA.
Official source (opens in a new tab)Does an IRMAA adjustment for one spouse automatically apply to the other?
No. SSA's new-initial-determination policy applies to the beneficiary requesting it. The other affected spouse must contact SSA independently, even when a joint return is used.
Official source (opens in a new tab)Can I ignore other taxable income after retiring?
No. Use total AGI plus tax-exempt interest, including taxable retirement distributions and taxable investment gains already reflected in AGI. A qualifying work stoppage does not make unrelated taxable income disappear. An SSA-44 request is not an automatic approval.
Official source (opens in a new tab)Is every Roth conversion or home sale a qualifying life-changing event?
No. Those income events alone ordinarily do not qualify for SSA-44. A separate qualifying work stoppage or another recognized event may require review. Community reports of successful appeals do not establish eligibility for a different person's circumstances.
Official source (opens in a new tab)Does IRMAA always begin at age 65?
Coverage is what matters in this calculator. Some people qualify for Medicare before 65, and people can have different enrollment dates. Enter the actual covered months instead of relying on a universal age-63 planning rule.
Official source (opens in a new tab)What is IRMAA?
The income-related monthly adjustment amount is an additional Part B and Part D premium for beneficiaries whose modified adjusted gross income exceeds an annual threshold. It is not a separate plan or a tax.
Why is SSA using income from two years ago?
IRMAA is ordinarily based on the federal tax return from two years before the premium year. For 2026 premiums, that is normally the 2024 return. SSA may use three-year-old information when the normal return is unavailable.
Does tax-exempt municipal bond interest count?
Yes. IRMAA MAGI is federal AGI plus tax-exempt interest, even though that interest is generally excluded from federal taxable income. It is reported on Form 1040 line 2a.
Is $38.99 the Part D premium I will pay?
No. $38.99 is the 2026 national base beneficiary premium, a statutory benchmark. Actual Part D plan premiums vary by plan and location. Part D IRMAA is a separate surcharge added on top of a plan premium.
Can a Roth conversion increase IRMAA?
A taxable Roth conversion can increase AGI and therefore Medicare MAGI. Because of the two-year lookback, a 2026 conversion ordinarily affects 2028 premiums. A Roth conversion is not itself an SSA-44 life-changing event.
Will selling my house increase IRMAA?
Any reportable taxable gain can increase MAGI. Gain excluded under the primary-home exclusion generally does not. A home sale alone is not a qualifying SSA-44 life-changing event merely because income later decreases.
Does IRMAA apply to both spouses?
IRMAA is assessed separately for each Medicare beneficiary. For a joint return, both spouses use the household MAGI but each enrolled spouse can receive a separate surcharge. A single combined household surcharge is not the right model.
What happens if we file married filing separately?
SSA generally assumes MFS spouses lived together at some point in the tax year and applies the accelerated schedule, which jumps to published surcharge levels 4 and 5. If the spouses lived apart for the entire year, SSA may apply the individual schedule after accepting an attestation under penalty of perjury. The adjustment applies only to the spouse who attests.
Can I appeal after I retire and my income drops?
A work stoppage or work reduction may qualify for a new initial determination using more recent income. SSA decides eligibility; this application does not. The appeal preparation guide explains the routes and the limits.
Is this calculator an official SSA decision?
No. It is a deterministic planning calculator using published rates. Actual SSA determinations, plan premiums, future rates, and individual exceptions control.
Glossary
AGI
Adjusted gross income from the federal return. It is the starting point for IRMAA MAGI.
MAGI
For IRMAA, federal AGI plus tax-exempt interest. Other programs use different MAGI definitions.
IRMAA
The income-related monthly adjustment amount added to Medicare Part B and Part D premiums.
Part B
Medicare coverage for physician services, outpatient care, and certain other services. The standard premium applies to most enrollees.
Part D
Medicare prescription drug coverage, usually delivered through a standalone plan or a Medicare Advantage plan.
Plan premium
The amount a Part D or Medicare Advantage plan charges for coverage. It is separate from IRMAA.
Base beneficiary premium
A statutory Part D benchmark ($38.99 for 2026), not a universal plan premium.
Premium year
The calendar year whose Medicare premium is being determined.
Lookback year
The tax year whose return is ordinarily used for the premium year, usually premium year minus two.
QSS
Qualifying surviving spouse with a dependent child; uses the individual Medicare rate schedule.
MFJ
Married filing jointly; uses the joint Medicare rate schedule.
MFS
Married filing separately. The applicable schedule depends on whether the spouses lived together during the tax year.
Tax-exempt interest
Interest excluded from federal taxable income, generally municipal bond interest, but still added to IRMAA MAGI.
New initial determination
An SSA redetermination after a qualifying life-changing event, often reported on Form SSA-44.
Reconsideration
A formal request to review an SSA determination, often using Form SSA-561.
Life-changing event
One of SSA's recognized events that may support a new initial IRMAA determination.
Citation registry
Each citation records its publisher, publication or effective date, verification date, and whether it was read during this release's regulatory review or is provided as an official reference link.
Sources used in the calculation
Who is eligible for Medicare?
Supports enrollment-based examples rather than a universal age-65 assumption. The calculator does not determine enrollment eligibility.
Open official source (opens in a new tab)IRS 2025 Form 1040
Verified as the 2025 revision on October 24, 2026; the current-form URL may change. The archived copy records the form actually reviewed.
Open official source (opens in a new tab)IRS Notice 2023-75 — 2024 retirement limits
Tax-year cap, not a Medicare premium-year limit. QCD eligibility and other restrictions still apply.
Open official source (opens in a new tab)IRS Notice 2024-80 — 2025 retirement limits
Use the distribution tax year. This cap alone does not establish QCD eligibility or a deductible amount.
Open official source (opens in a new tab)IRS Notice 2025-67 — 2026 retirement limits
2026 distribution-year rule; its ordinary Medicare linkage is 2028, whose rates are not bundled.
Open official source (opens in a new tab)CMS 2025 Part D bid information and premium stabilization
Added in historical pack revision 2025-official-v2. Benchmark only; actual plan premiums remain separate.
Open official source (opens in a new tab)IRS 2023 Form 1040
Read the year-specific IRS form during the October 23, 2026 audit.
Open official source (opens in a new tab)IRS 2024 Form 1040
Read the year-specific IRS form during the October 23, 2026 audit.
Open official source (opens in a new tab)2026 Medicare Parts A & B Premiums and Deductibles
Primary source used for every 2026 premium, threshold, and surcharge in the bundled official pack.
Open official source (opens in a new tab)2026 Medicare Part D Bid Information and Part D Premium Stabilization Demonstration Parameters
Used only for the Part D benchmark disclosure. It is never added to a user's premium as though it were a plan premium.
Open official source (opens in a new tab)2025 Medicare Parts A & B Premiums and Deductibles
Primary source for the bundled historical 2025 pack.
Open official source (opens in a new tab)POMS HI 01101.010 — Modified Adjusted Gross Income (MAGI)
POMS TN 36 (12-25). Used for the MAGI formula and lookback rules.
Open official source (opens in a new tab)POMS HI 01101.020 — IRMAA Sliding Scale Tables
Corroborates the CMS 2026 tables. Also explains that SSA assumes MFS couples lived together unless an attestation establishes otherwise.
Open official source (opens in a new tab)POMS HI 01120.060 — Married, Filing Separately — Lived Apart All Year
Each spouse must separately establish the lived-apart request. An MFS household estimate uses the selected factual living arrangement for both people, but does not establish either person's SSA approval.
Open official source (opens in a new tab)POMS HI 01120.001 — New Initial Determination
Reviewed for beneficiary-specific requests and the distinction from reconsideration. No eligibility engine is implemented.
Open official source (opens in a new tab)POMS HI 01120.005 — Life-Changing Events
Reviewed for educational event/income guidance; SSA decides the requested year and eligibility. No eligibility engine is implemented.
Open official source (opens in a new tab)IRS Publication 590-B — Distributions from Individual Retirement Arrangements
Reviewed for QCD educational guidance: age, direct transfers, annual caps and the deductible-contribution offset. No eligibility or tax-savings calculator is implemented.
Open official source (opens in a new tab)
Further official references
POMS HI 01140.001 — IRMAA Appeal Procedures
Official appeal preparation resource.
Open official source (opens in a new tab)Form SSA-44 — Medicare Income-Related Monthly Adjustment Amount — Life-Changing Event
The application does not submit this form. Read the appeal preparation guides and current official instructions.
Open official source (opens in a new tab)Form SSA-561 — Request for Reconsideration
A new initial determination and a formal reconsideration are different routes; the product must not merge them.
Open official source (opens in a new tab)Social Security Act § 1839(i)
Legal authority for the Part B sliding scale.
Open official source (opens in a new tab)Social Security Act § 1860D-13
Legal authority for Part D IRMAA.
Open official source (opens in a new tab)20 CFR Part 418 — Medicare Income-Related Monthly Adjustment Amount
Regulatory framework cited by SSA POMS.
Open official source (opens in a new tab)IRS Form 1040 — U.S. Individual Income Tax Return
The 2024 mapping is corroborated by SSA POMS. The 2025 form is separately verified under irs-form-1040-2025; no official 2027 premium pack is bundled.
Open official source (opens in a new tab)IRS Publication 969 — Health Savings Accounts and Other Tax-Favored Health Plans
Official tax guidance; eligibility is not calculated here.
Open official source (opens in a new tab)IRS Publication 523 — Selling Your Home
Official home-sale tax guidance; taxable gain must be established separately.
Open official source (opens in a new tab)
Regulatory data version
| Pack | 2026 official |
|---|---|
| Revision | 2026-official-v1 |
| Normal tax year | 2024 |
| Fallback tax year | 2023 |
| Published | November 14, 2025 |
| Independently verified | October 23, 2026 |
| 2027 rates | No independently verified 2027 schedule is bundled in this release, reviewed as of October 24, 2026. The app will not estimate one from prior-year values. |
See methodology and privacy for the engine and data-handling details. View source archive dates, dataset revisions, and SHA-256 digests.