Medicare Cost Planner

What it does

Computes annual Medicare costs given your filing status and modified AGI — Parts A/B/D premiums plus IRMAA surcharges that kick in at $109K/$218K and step up through 5 more tiers. Includes cliff warnings if you're sitting just below an IRMAA threshold.

Who this helps

Anyone 64+ planning Medicare enrollment, or any retiree managing AGI to avoid IRMAA tiers. Roth conversions, capital gains, and large RMDs can all push you into surprise tiers.

How to use it

1. Pick filing status.
2. Enter Modified AGI from two tax years prior (2026 premiums tie to 2024 income).
3. Choose plan type: Original Medicare + Medigap + Part D, Medicare Advantage, or bare Original.
4. Set your Medigap/Part D/Advantage premium estimates.
5. Read the tier table — your tier is highlighted, and any cliff-warning under \$5K to the next tier is flagged.

What it doesn't do

IRMAA values are 2026 estimates derived from CMS 2024-2025 figures + ~3% projection. Real CMS releases yearly in October. Doesn't model the IRMAA 'life-changing event' appeal (Form SSA-44) for retirees whose income just dropped.