Help & FAQ

These are year-by-year retirement planning tools. The Retirement Projection models how your accounts (pre-tax 401k/IRA, Roth, taxable brokerage) will be drawn down over time, estimating withdrawals, taxes, Medicare premiums, and ending balances through whatever age you choose.

The Tax Estimator breaks down a single year's federal income tax — useful for checking the bracket math for any specific age row. The Roth Conversion Optimizer finds the annual conversion amount that minimizes your lifetime federal tax bill.

None of this is financial advice. The numbers are estimates based on 2026 tax law and your inputs. Always verify with a qualified advisor.

• Pre-tax balance — your latest 401k/IRA statement total
• SS monthly benefit — your Social Security statement at ssa.gov/myaccount (look for "at full retirement age")
• Return rate — historical average for a 60/40 portfolio is roughly 6–7% nominal; use 4–5% for a conservative estimate
• Div yield — a broad index fund (e.g. VTI) yields roughly 1.5–2%
• COLA — the Social Security Administration's long-run assumption is 2.5%; CPI has averaged ~2.8% over the past 30 years

It's your total desired gross income from all sources combined — pre-tax withdrawals, Roth withdrawals, Social Security, and taxable dividends. The calculator works backward from this target to decide how much to pull from each account.

The target is expressed in today's dollars and scaled by COLA each year, so your real purchasing power stays constant throughout the projection.

Note: once RMDs begin, the forced withdrawal may exceed or fall short of your target. The calculator tops up from Roth if short, or shows the excess if the RMD overshoots.

Before RMDs start, the calculator uses a binary search to find the largest pre-tax withdrawal that keeps your ordinary taxable income at or just below the 24% bracket ceiling. Any remaining gap to your target income is filled from Roth (tax-free).

The Strategy column in the table tells you what happened each year:

• ✓ In bracket — pre-tax alone stayed within 24%
• ⟳ Roth shield — pre-tax was capped at the bracket ceiling; Roth filled the gap
• ↑ Above 24% — income pushed above the ceiling (e.g. large SS + RMD year)
• ⚡ RMD forced — IRS-mandated withdrawal, bracket ceiling ignored
• ⬇ Taxable tap — both pre-tax and Roth accounts exhausted; pulling from taxable principal

Up to 85% of your SS benefit can be taxed as ordinary income depending on your provisional income (PI = pre-tax withdrawals + dividends + 50% of SS).

• PI below $25k single / $32k MFJ → 0% of SS taxable
• PI $25k–$34k single / $32k–$44k MFJ → up to 50% taxable
• PI above $34k single / $44k MFJ → up to 85% taxable

These thresholds are not inflation-adjusted by law — they've been frozen since 1984/1993 — so more of your SS becomes taxable each year in real terms. The calculator applies these correctly every year.

Required Minimum Distributions are IRS-mandated annual withdrawals from pre-tax accounts (401k, traditional IRA). The amount is calculated by dividing your prior year-end balance by a life expectancy factor from the IRS Uniform Lifetime Table.

Start age depends on your birth year (SECURE 2.0 Act):

• Born 1950 or earlier → RMDs started at 72
• Born 1951–1959 → RMDs start at 73
• Born 1960 or later → RMDs start at 75

Roth IRAs have no RMDs during your lifetime. Roth 401ks inherited that exemption under SECURE 2.0 as well.

IRMAA (Income-Related Monthly Adjustment Amount) is a Medicare Part B and Part D surcharge for higher-income retirees. It's based on your MAGI from two years prior (e.g. your 2024 income determines your 2026 IRMAA).

The calculator applies the 2026 IRMAA tiers (from the CMS final rule) and scales thresholds and premiums by COLA each year as a conservative estimate. Roth withdrawals do not count toward IRMAA — one reason Roth conversions before retirement can significantly reduce Medicare costs.

It depends on your current vs future tax rate. If you're in the 22% bracket now but SS + RMDs will push you to 32% later, converting today means paying 22¢ per dollar instead of 32¢. The conversion window cards show you the exact tradeoff: extra tax paid now vs lifetime savings.

The optimizer's "lifetime tax with conversion" number already includes the upfront conversion tax — so if it's lower than the "no conversion" number, you genuinely come out ahead even after paying more now.

Window A (withdrawal start → SS claim) is typically the most powerful window. Before SS starts, your only income is account withdrawals, so you're in the lowest brackets of your retirement. Every dollar converted now is converted at that low rate.

Window B (withdrawal start → RMD start) is longer. More years of conversion means more total dollars shifted, but if SS starts mid-window, your bracket headroom narrows.

The optimizer computes the optimal amount for each window independently and recommends whichever saves more in net lifetime tax. The "apply to projection" button uses the recommended window's range.

Sometimes, yes. Conversion only helps if your future marginal rate exceeds your current conversion rate. If your pre-tax balance is small, SS is modest, and RMDs won't push you into a high bracket, there may be nothing to gain.

Try increasing the "Tax rate on future RMD income" input to reflect a more pessimistic assumption — if that flips the recommendation, conversions become worthwhile only under that scenario.

All base numbers use 2026 tax law, including:

• Brackets and standard deductions from IRS Rev. Proc. 2025-32
• Additional senior deduction (age 65+) — $2,050 single / $1,650 per spouse MFJ
• OBBBA senior bonus deduction — $6,000 single / $12,000 MFJ, phases out above $75k/$150k MAGI
• LTCG rates from IRS Rev. Proc. 2025-32
• IRMAA tiers from CMS final notice (Nov 14, 2025)

Future years scale bracket thresholds, standard deductions, and IRMAA thresholds/premiums by the COLA rate you enter. SS provisional income thresholds ($25k/$34k single, $32k/$44k MFJ) are not scaled — they're frozen in statute.

The year SS starts is often a tax bump year. SS triggers provisional income calculations, which can make up to 85% of your benefit taxable — and that taxable SS stacks on top of your account withdrawals. At the same time, Medicare (IRMAA) kicks in at 65.

The best mitigation is Roth conversions before SS starts — reducing your pre-tax balance means smaller RMDs and less SS taxability later. The Roth Conversion Optimizer is designed specifically for this.