📞 213-414-2808
SIS · RMD · Roth · IRMAA · all at once

Tell me the optimal SIS term — given my retirement.

Enter your sale + your retirement profile. The optimizer runs every SIS term from 5 to 40 years, layers in your RMDs, Roth conversion headroom, Social Security taxation, IRMAA cliffs, and California progressive brackets — then ranks them. Every number is explained.

1. The sale

What you're selling. Pulled from the SIS calculator if you came from there.

2. You + your retirement

The data the optimizer needs to layer RMDs + Roth + SS on top of your SIS.

3. Strategy + assumptions

What you're optimizing for and the long-horizon assumptions.

Tests SIS terms from 5–40 yrs, simulates each through your expected death age, ranks by your objective.
Recommended

— yr SIS

—
Lifetime after-tax cash
—
today's $, discounted
Total Roth converted
—
tax-free to heirs
RMDs eliminated by age
—
IRA fully converted by

Every SIS term, ranked

Each row simulates the full lifetime through your expected death age. Green = your sweet spot. Red = avoid.

Term SIS net (FV) Lifetime tax Roth converted IRMAA hits Estate value Verdict
How the scoring works

Year-by-year ledger (winning term)

Every year of your retirement, with Roth conversion + RMD + SS taxation + IRMAA modeled.

YrAgeSIS
princ.		SIS
int.		SS taxableRMDRoth
convert		Total
taxable		BracketIRMAA
tier		Total taxNet cashIRARothOutside
cash
Show the math for any year
Click any row in the table to see the full per-year tax breakdown (Federal LTCG + Federal Ord + NIIT + CA progressive + MHST + IRMAA tier).
Calculator transparency

Exactly what's modeled — and what needs a 20-min consult.

The calculator handles the core 80% of the math. The other 20% — the edge cases below — is where real planning happens. If any apply to your situation, that's the conversation worth having.

✓ What this calculator models
  • Federal LTCG progressive 0/15/20% with stacking · IRC §1(h)
  • Federal ordinary income tax with full bracket math · IRC §1
  • California progressive 1–13.3% with stacking · CA R&TC §17041
  • CA Mental Health Surtax 1% over ~$1M MAGI · CA R&TC §17043
  • NIIT 3.8% on investment income · IRC §1411 (statutory threshold, not indexed)
  • §121 home exclusion $500K MFJ / $250K Single
  • §1250 depreciation recapture 25% federal cap + CA
  • Social Security taxation 0/50/85% tiers · IRC §86 (LTCG included in provisional)
  • RMDs with correct start age 73 or 75 · SECURE 2.0 · IRS Uniform Lifetime Table
  • Roth conversion ladder with bracket ceiling + cash-flow constraint
  • IRMAA Medicare surcharge with 2-year MAGI lookback · SSA POMS HI 01101.020
  • Bracket inflation 2.5%/yr (user-configurable)
  • SIS amortization declining-balance interest · IRS Pub 537
  • §453A interest charge on installment obligations >$5M · IRC §453A(c)
  • Annual brokerage LTCG stacks as cap gain, not ordinary
  • Discount to today's $ at user-set real rate
⚡ What needs a 20-min consult
  • §453A interest charge — now modeled, but uses simplified 20% federal cap gains assumption + 5.8% underpayment rate. Your actual case may use different rates.
  • §1202 QSBS exclusion — founders selling startup stock can exclude up to $10M / 10× basis. Often saves $2M+.
  • §1245 ordinary recapture — business sales with depreciated equipment (ord rates, not 25%)
  • City transfer tax — SF (~0.75%), LA Measure ULA (4–5.5% over $5M), Berkeley, Oakland
  • AMT exposure — rare post-TCJA but possible (large ISOs, certain deductions)
  • IRD at death — heirs inherit SIS income-tax obligation, no step-up basis
  • Multi-state source taxation — CA may still tax SIS after you move out of state
  • Carryforward NOLs / loss harvesting — could offset cash-sale tax
  • Trust structures — GRAT, IDGT, ILIT have specific tax treatment
  • CRT (Charitable Remainder Trust) comparison — alternative or supplement to SIS
  • Estate tax exposure — federal $13.6M exemption (sunsets ~$6M post-TCJA)
  • QCD strategy — direct IRA-to-charity after 70.5 (satisfies RMD, no AGI hit)
  • Pro-rata IRA basis rule — affects Roth conversion if you have nondeductible IRA $
  • Spouse SS optimization — joint claiming strategies
  • K-1 / lumpy income events — year-specific cash flows
  • Future tax law — TCJA sunset, RMD age, IRMAA recalibration
If any of those edge cases apply to your situation — that's the conversation.

The calculator gets you 80%. The other 20% is what closes the gap between "interesting math" and "right for me."

📞 Book a 20-min consult — 213-414-2808
Take this with you

Save this analysis · Email it to yourself or your CPA

Save a beautiful PDF for your records, or have Hans send it to you (or directly to your CPA) from [email protected] with the full math breakdown and IRS citations.

PDF saves locally. Email comes from [email protected] with the full report inline.
Four tools, one math engine

Each calculator answers a different question. Pick the one that fits yours.

⚡ 30-sec gut check
Quick Calculator
"Should I even consider SIS?"
4 inputs only — sale, basis, income, term. One number out. Bracket-math expander shows the work.
Skip if: you need multi-year planning, QSBS/§1245, or retirement modeling.
Open Quick →
🔬 Tax-forensic · 5 min
Tax-Detail Calculator
"What's my exact year-1 tax bill?"
Every factor a CPA cares about: §1202 QSBS · §1245 · §453A · §199A QBI · city transfer tax · §121 · prior 1031 carry. Color-coded live math breakdown — every formula visible.
Skip if: you want lifetime planning or bucket allocation.
Open Tax-Detail →
💰 Bucket strategy · 5-8 min
Cash-Flow Planner
"How do I split the proceeds?"
Allocates proceeds across liquid buckets (HYSA + MYGA) and SIS. Models deferred SIS start age, multi-phase income (working → retired), apples-to-apples after-tax yield, inflation-adjusted IRR.
Skip if: you just want the tax answer or you're age 55+ and need RMD/Roth modeling (use Lifetime).
Open Cash-Flow Planner →
🎯 Lifetime plan · 5-10 min
Lifetime Optimizer
"What's my whole retirement plan?"
Optimizes SIS term 5-40 yrs across your full retirement. Models RMDs (age 73/75), Roth conversion ladder, SS taxation (0/50/85%), IRMAA 2-yr lookback, bracket inflation. Year-by-year ledger with IRS citations on every formula.
Skip if: you don't have a pre-tax IRA/401k or you just want the year-1 number.
Open Lifetime Optimizer →
Honest order: If you're new here, start with Quick. If your CPA needs to verify the math, send them Tax-Detail. If you're planning how to actually deploy the proceeds, use Cash-Flow Planner. If you're age 55+ with a pre-tax IRA, the Lifetime Optimizer is the strongest tool. All four show the math.
Educational only — not tax, legal, or investment advice. Brackets, IRMAA tiers, and RMD divisors are 2026 base year values inflated forward at the rate you set. Future tax law (TCJA sunset, RMD age changes, IRMAA recalibration) is unknown — this is a best-effort projection, not a guarantee. NIIT threshold ($250K MFJ / $200K Single) is statutory and does not index — gets relatively tighter every year. CA source taxation if you move out of state is a gray area not modeled here. SS payments are treated as 100% Social Security for taxation regime purposes; if your "Other income" includes pension, the model approximates by treating it as ordinary income (which is correct). IRD treatment at death for SIS payments is significant and is not modeled in v1. Confirm with your CPA and tax attorney before acting.