Inputs
Retirement (2028)
Medicare (2051)
Social Security starts
Year-by-Year Federal Tax Projection
Year Age Ord Income LTCG Std Ded Taxable Ord Fed Tax Eff Rate LTCG Tax Total Tax MAGI ACA Cliff Headroom IRMAA Sur.
Note: Colorado state income tax (~4.40% flat rate) is not included. Estimated CO state tax: add ~4.40% × (federal taxable income) ≈ $2,000โ€“3,500/yr for typical retirement income of $50โ€“80K taxable.
⚠ IRMAA Spike Alert: When SS income begins in 2053+ (Courtney) and 2056+ (Scott), MAGI will jump ~$35โ€“50K/yr. The 2-year IRMAA lookback means 2055โ€“2058 Medicare Part B/D surcharges will reflect this higher income. Plan Roth conversions in 2051โ€“2054 carefully to minimize IRMAA tier exposure.
Roth Conversion Capacity (2028โ€“2052)

Max additional conversion staying within 12% bracket & ACA cliff (base income excludes Roth conversion)

Year 12% Ceiling Base Ord Inc Max Conv @12% ACA Headroom Binding Limit Tax @12%
0% LTCG Harvest Capacity (2028โ€“2052)

Room to realize long-term gains at 0% federal rate (based on base ordinary income, no Roth conversion)

Year 0% LTCG Threshold Ord Taxable (no conv) Harvest Capacity Effective Rate on Harvest
Note: 3.8% Net Investment Income Tax (NIIT) applies if MAGI exceeds $250,000 MFJ. This household is unlikely to trigger NIIT under normal conditions, but a large Roth conversion or inheritance year could push MAGI above this threshold.
Tax-Efficient Withdrawal Order โ€” Lifetime Strategy

Based on Kitces/Pfau research and i-ORP principles: minimize lifetime taxes by sequencing withdrawals to avoid bracket jumps, ACA cliff, and IRMAA surcharges.

Phase Years ยท Ages Primary Source Key Constraint Roth Conversion Opportunity Tactical Notes
Priority Rule: Taxable first (up to 0% LTCG threshold or ACA cliff) โ†’ Traditional IRA/401k (fill remaining bracket room) โ†’ Roth last (preserve tax-free compounding). Exception: RMD years โ€” traditional comes out first by law. Use QCDs if charitable.
Roth Conversion โ†’ RMD Impact Projector

How much will your conversions reduce your required minimum distributions at age 73 (2059)? Assumes 6.5% growth on tax-deferred accounts.