Seraph

Retirement Planner

When can I retire? How much can I spend?

Your retirement will only happen once: one market, one lifespan, nobody knows which. Seraph runs thousands of possible versions of it, taxes and healthcare included, and shows you where your plan holds up and where it breaks.

Download on the App Store See how it works

What it does

Your whole retirement, stress-tested

Answer five quick questions and you'll see your first number in under a minute. Then make the plan yours: every scenario gets stress-tested across thousands of futures and drawn out as a story you can actually read. No spreadsheets, and no pretending anyone can predict the market.

Run a thousand lifetimes

Monte Carlo puts your plan through thousands of market paths and lifespans. See your median net worth, your chance of staying solvent, and where the good and bad tails land.

See what moves the needle

Drag one lever (inflation, returns, spending) and watch the plan react live. The tornado ranks every lever by impact, so you know what's worth worrying about.

Compare money moves

Line scenarios up side by side: "keep working" vs "retire now," this house vs that one. Flip between today's dollars and nominal in a single tap.

Keep score in the Journal

Log your real net worth over time (investments, retirement accounts, cash, home, debts) and watch the actual line grow next to the plan. Your safety net too: back it all up to your own iCloud or a file.

The engine

What the model covers

Social Security

Claiming ages 62 to 70
Spousal and survivor benefits
Benefit taxation, federal and state
A benefit-cut what-if

Taxes

2026 federal, all 50 states, and NYC
Capital gains brackets, the 0% bracket included
Capital-loss carryforward
Payroll tax while you work
Filing status, including the survivor's switch to single
State-by-state rules for retirement income
State quirks, like NJ and CA taxing HSA contributions

Retirement moves

Roth conversions, filled to the bracket you choose
Required minimum distributions
SEPP 72(t) early withdrawals
Surplus income swept into your 401(k)

Accounts

Brokerage, pre-tax, Roth, HSA, and cash
Roth basis tracked through every year
Pensions
Lifetime annuities priced on real mortality tables

Healthcare

Employer coverage, then the ACA bridge to 65
ACA subsidies and cost sharing from your simulated income
Medicare Parts B and D
IRMAA surcharges
State quirks, like the Medicaid coverage gap in the ten non-expansion states

Life and home

Couples modeled as two lives
Personalized longevity from your health profile
Buying, selling, and downsizing homes, mortgage included
The capital gains exclusion when you sell

Markets and mortality

The two hardest things in a retirement model are the market and the lifespan, and this one treats both the way banking and insurance do. Returns come from a correlated multi-asset model with stochastic inflation, the machinery banks use to stress portfolios over decades. Lifespans are simulated from the Social Security Administration's life tables with mortality improvement, the machinery insurers use to price promises that have to hold for a lifetime. Our team built these models professionally before building this app.

Ask bigger questions

What can you actually ask it?

All that machinery exists so the plan can hold the messy questions real retirements are made of. A few it answers well:

Should I claim Social Security at 62 or 70?

It models the real actuarial reduction and delayed credits, survivor benefits, and how much of your check actually gets taxed, then shows you the crossover.

What does retiring before 65 really cost?

Marketplace premiums bridge you to Medicare, and the plan estimates your ACA subsidy every year from your simulated income: the 400% cliff, your state's rules, cost sharing reductions, even your kids while they count. Then Part B, Part D, and IRMAA take over.

Should I buy the annuity my advisor is pitching?

Price a lifetime annuity against real mortality tables, the insurer's cut included, and see whether the guarantee earns its keep in your plan.

What happens to the one of us who's left?

Couples are modeled as two lives: survivor benefits, the switch to filing single, and the tax squeeze that follows. It's not a fun question, which is exactly why the plan should hold it.

The signature view

See the whole story unfold

Median liquid net worth, building through your working years and drawing down in retirement. Retire a little later and the line rides higher, longer; retire early and it cuts closer. Every lever you touch redraws it.

Net Worth

Median liquid net worth by age

Retire at 67 Retire at 62 Shaded: middle half of outcomes

SAMPLE PLAN · RETIRE AT 62

$925k

Median net worth at 80

71%

Chance solvent at 80

51%

Success over a random lifespan

87 / 90

Life expectancy (you / spouse)

Illustrative projection, not a forecast of your results. In the app these numbers are yours: every input, every lifetime, recalculated live.

The Seraph blog

One question at a time, with receipts

On the blog we take a single retirement question, build a real household around it, and run it through the same engine that's in the app. Real projected numbers, no ten-tips listicles.

Read the blog

See your own odds

Seraph: Retirement Planner is on the App Store for iPhone & iPad. Free, no account needed, and the financial data you enter never leaves your device.

Android coming soon. Drop your email and we'll send one note when it lands.

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