Your financial life, kept as a set of books.

A projection should balance before it persuades.

Most retirement tools begin with a handful of inputs and jump to a probability or chart. RetireOdds begins with the books: what you own, what kind of account holds it, what comes in, what goes out and what remains unpaid.

A retirement decision is rarely changed by investment returns alone. The same withdrawal can create a capital gain, ordinary income, no federal income, a Roth penalty, an ACA subsidy change or an IRMAA surcharge two years later. Collapsing every dollar into one balance loses the information needed to model those consequences.

The RetireOdds ledger preserves that information through time. Every modeled year has an opening position, categorized activity, source-aware settlement, a tax and healthcare record, and a closing position that rolls into the next year.

Real inputs become one canonical record.

RetireOdds does not continuously scrape your financial institutions. You control the record: enter facts manually or upload brokerage and expense files, review what changed, and confirm the books that drive the plan.

Inputs carry provenance

Account classifications, basis records, as-of dates and imported positions are not decorative metadata. They determine whether a withdrawal is a taxable sale, an ordinary distribution or a Roth distribution. File imports use snapshot reconciliation: matching positions are updated, absent positions can be removed after confirmation, cash is replaced rather than added, and repeated imports are designed to be idempotent.

Missing facts stay visible

If a material input is absent, such as account tax treatment, cost basis, investment-income character or a valuation date, the product raises a review action. It does not silently turn unknown data into a confident result. Where a conservative fallback is necessary, the assumption is disclosed.

Every year must explain where the money went.

A ledger year is a cash-and-balance reconciliation, not just a return calculation. The exact rows vary by phase and enabled features, but the conservation rule does not.

Where an exact equation is available, RetireOdds calculates its residual and treats a difference greater than one cent as unreconciled. The ledger also distinguishes balances, cash flows, transfers, tax metrics and non-spendable values so a transfer cannot be mistaken for income and illiquid NAV cannot quietly pay a bill.

A dollar's source changes what it can do.

RetireOdds keeps market value separate from statutory basis and keeps liquid wealth separate from assets that cannot fund spending today.

Settlement is source-aware

When cash is needed, the engine uses the selected withdrawal order and the legal character of the available source. A taxable sale realizes only its gain portion; a tax-deferred distribution creates ordinary income and can recover entered IRA basis pro rata; a Roth distribution follows contribution, conversion and earnings ordering. Taxes created by the draw are included in the amount that must be funded.

Basis survives market losses

Market value and statutory basis are different records. A decline in Roth market value does not erase historical contribution basis. A taxed dividend can increase taxable cost basis when reinvested. A return of capital reduces alternative-asset basis before later gains are characterized.

The books begin today, not at retirement.

The same annual architecture covers the current year, working years, retirement years and the final plan settlement. This prevents pre-retirement activity from bypassing tax, healthcare or source rules.

The primary person's age is the shared axis. A spouse is represented by an age offset, so claim dates, Medicare eligibility, survivor tax status and each person's horizon remain tied to the same calendar year rather than drifting across two independent timelines.

Depth without a second set of answers.

Complex features add characterized facts to the annual record. They do not create disconnected calculators with their own balances or year conventions.

Every consequential number should have a receipt.

Click an underlined Ledger amount to open its explanation. The side panel is generated from the selected cell's typed provenance, not generic help text.

A trace can include the output cell ID, financial phase, treatment, source facts, source-page links, input references, decision references, rule ID, model version, exact unrounded result and downstream cells. Where an exact formula exists, the panel shows the terms, result and residual. Where detailed provenance is not available, RetireOdds does not show an empty “breakdown.”

This makes review practical. You can move from a tax number to Tax Planning, from spending to Expenses, or from an account balance to Portfolio, change the underlying fact and regenerate every downstream year.

A scenario is a temporary second set of books.

What-if analysis is useful only when the alternative keeps the same accounting discipline as the baseline.

The preview request is allowlisted and never writes back to your saved plan. Changed assumptions re-resolve dependent ages, healthcare, taxes, life events and horizon values instead of editing one headline in isolation. A country preview, for example, reprices living costs, healthcare, inflation, FX and coordinated tax assumptions as one server-owned bundle.

Withdrawal-strategy comparisons are different: the annual table remains the deterministic reference plan, while paired stochastic runs compare market-path outcomes under the selected strategy. Both runs still begin with the same resolved plan and common random seed.

Monte Carlo sits on top of the ledger.

The deterministic books explain one internally consistent plan. Simulation asks how often that plan remains funded when market returns, longevity and other enabled uncertainties change.

Monte Carlo and bootstrap run 1,000 paths by default. Each path walks the same life stages and re-solves source-aware withdrawals, taxes, MAGI, healthcare, conversions, RMDs and enabled cash flows against that path's balances. A path fails when any after-tax obligation remains unfunded, including in the final modeled year. A zero portfolio is still successful when outside income fully covers every obligation.

The Chance screen also preserves the other side of the percentage. Where this plan fails counts the exact paths that left an obligation unfunded, groups their first-shortfall ages into real five-year bands, and shows one to three actual failed trials selected deterministically from the early, middle and late ranks of failure timing. The ages and gaps are conditional on failed paths only. These examples come from the same run as the headline success rate; they are not forecasts, causal diagnoses or synthetic percentile paths.

How to read the results

• Plan success is the share of paths in which every modeled year is funded. It is not a guarantee.
• P10, P50 and P90 are the 10th percentile, median and 90th percentile ending balances for each future year.
• Median funded spending reports what the paths actually funded, which matters when a strategy flexes spending.
• At 1,000 paths, a mid-range success estimate has roughly a ±3 percentage-point sampling margin at 95% confidence, before model uncertainty.

All primary planning values use real, today's-dollar terms. Explicit nominal return assumptions are converted through the Fisher relation: (1 + nominal) / (1 + inflation) − 1.

The architecture is designed to expose drift.

Financial software becomes unreliable when each screen assembles a slightly different version of the household. RetireOdds uses mechanical constraints and parity tests to make that divergence visible.

A complete model still has boundaries.

RetireOdds aims to make material simplifications explicit. The Ledger is planning-grade financial software, not a tax return, legal opinion or promise about markets.

No model predicts the future. A success rate measures robustness across the assumptions and paths that were modeled. It does not measure every risk and is not a recommendation to buy, sell, convert, claim or retire.

The rules are tied to published sources.

Tax, healthcare and retirement constants are pinned to a stated model year and updated together. Primary authorities take precedence over summaries or memory.