This dataset lists the 2026 Medicare Income-Related Monthly Adjustment Amount (IRMAA) brackets: for each filing status and tier, the MAGI floor at which the surcharge applies, the monthly Part B and Part D surcharge, and the annualized totals. MAGI here is the amount reported on the tax return from two years prior (the CMS lookback year). The table is sortable by any column; the full data is also available as CSV and JSON below.
What this is: A structured, per-tier snapshot of the IRMAA surcharge schedule that matters most for Roth-conversion and withdrawal timing — pulled directly from the same functions that power the QuantCalc calculator, so the numbers here are never out of sync with the app.
Full dataset (10 rows)
Click any column header to sort. All 10 rows are shown, or download the CSV/JSON for offline analysis.
| Filing Status | Tier | MAGI Floor | Part B Surcharge (Monthly) | Part D Surcharge (Monthly) | Part B Surcharge (Annual) | Part D Surcharge (Annual) | Total Surcharge (Annual) |
|---|---|---|---|---|---|---|---|
| Single | 1 | $109,000 | $81.20 | $14.50 | $974.40 | $174.00 | $1,148.40 |
| Single | 2 | $137,000 | $202.90 | $37.50 | $2,434.80 | $450.00 | $2,884.80 |
| Single | 3 | $171,000 | $324.60 | $60.40 | $3,895.20 | $724.80 | $4,620.00 |
| Single | 4 | $205,000 | $446.30 | $83.30 | $5,355.60 | $999.60 | $6,355.20 |
| Single | 5 | $500,000 | $487.00 | $91.00 | $5,844.00 | $1,092.00 | $6,936.00 |
| Married Filing Jointly | 1 | $218,000 | $81.20 | $14.50 | $974.40 | $174.00 | $1,148.40 |
| Married Filing Jointly | 2 | $274,000 | $202.90 | $37.50 | $2,434.80 | $450.00 | $2,884.80 |
| Married Filing Jointly | 3 | $342,000 | $324.60 | $60.40 | $3,895.20 | $724.80 | $4,620.00 |
| Married Filing Jointly | 4 | $410,000 | $446.30 | $83.30 | $5,355.60 | $999.60 | $6,355.20 |
| Married Filing Jointly | 5 | $750,000 | $487.00 | $91.00 | $5,844.00 | $1,092.00 | $6,936.00 |
CC-BY-4.0 — free for any use including republication and journalism, with attribution to QuantCalc Research.
Methodology
Source: Every dollar figure in this dataset is produced by calling frontend/js/calc/irmaa.js's exported getBrackets2026() and annualSurcharge() functions — not read as bare literals. Those functions read the MAGI-floor tier data from QCConstants2026.IRMAA_TIERS (constants-2026.js), QuantCalc's canonical client-side tax-constants mirror, transcribed verbatim from the frozen production C engine (backend/src/irmaa.c). Nothing on this page is hand-transcribed from a CMS notice into HTML.
Consistency: This mirror is checked against the C engine by an exhaustive JS↔C parity test suite that sweeps a dense grid of inputs and asserts numeric agreement. That suite is what lets this dataset, the interactive calculator, and the C backend all report the same figures. As an additional in-generator safeguard, every row's total annual surcharge from annualSurcharge() is cross-checked against the Part B + Part D annual sum from getBrackets2026() at build time; the generator aborts if they ever disagree.
Scope: Covers Single and Married Filing Jointly, the two filing statuses getBrackets2026() exposes. It does not include the Married Filing Separately (lived with spouse) compressed 2-step schedule, which follows different boundary rules — that is modeled in the engine (and in QCConstants2026.IRMAA_TIERS.mfs) but not surfaced as rows here in v2026.1.
Boundary rule: A tier applies only when MAGI strictly exceeds its floor, except the top tier whose floor is inclusive (MAGI ≥ floor). MAGI exactly on an interior floor stays in the lower tier.
Reproducibility: Generated by scripts/gen_irmaa_dataset.mjs, which calls into irmaa.js directly and writes this page plus the CSV/JSON alongside it. Re-running the generator against the same constants file reproduces byte-identical data rows.
Not tax advice: This is reference data for research and planning purposes, not a substitute for professional tax or Medicare advice. Consult a qualified advisor before making Medicare or income-timing decisions based on this table.
Turn these brackets into a conversion plan
Knowing where your MAGI sits relative to the next IRMAA tier is the first step. The Roth Conversion Planner accounts for the two-year IRMAA lookback when it builds your year-by-year conversion schedule.
Plan your Roth conversions →Changelog
- v2026.1 — initial release. 10 rows (2 filing statuses × 5 tiers), generated from
irmaa.js/constants-2026.js.
Dataset license: CC-BY-4.0. QuantCalc is an independent retirement-planning research project. Not affiliated with, endorsed by, or sponsored by any state or federal agency, including CMS or the Social Security Administration. Not financial, tax, or legal advice.