Glossary

Plain-language definitions of the terms you’ll meet in RetireRange. Where a concept has its own guide, there’s a link to dig deeper.

After-tax legacy — What your heirs would actually keep after the tax due on what they inherit, applied by account type: inherited Traditional and HSA balances are taxed at the heirs’ ordinary (+ state) rate, while Roth and Taxable pass at full value. The more realistic legacy number. See Understanding your results.

Asset allocation — Your mix of stocks, bonds, and cash. In RetireRange it’s set by how you build your accounts and stays fixed through the simulation (there’s no automatic glide path). See Limitations.

Bad-sequence overlay — A Results-tab toggle that drops the worst real starting points on record (1929, 1966, 2000, 2008) onto your trajectory chart, to see how your plan would have tracked through them.

Baseline — Your shared snapshot of where you stand today (current balances, the people in the plan, core assumptions). You update it when you reconcile your accounts; older saved scenarios get flagged stale. See Scenarios.

Bootstrap mode — A way of generating returns by stitching together blocks of actual market history (1928–2025) instead of a bell curve, preserving real-world crashes and patterns. See Assumptions tab.

CAGR (Compound Annual Growth Rate) — The geometric average return — what you actually experience as money compounds, accounting for the drag of volatility. Lower than the arithmetic mean for volatile assets, and the recommended return type. See Assumptions tab.

Cascade — When the account type you’re drawing from runs out, RetireRange automatically shifts withdrawals to the next-best type.

COLA (Cost-of-Living Adjustment) — An annual inflation increase applied to a benefit such as Social Security.

Deterministic — Without randomness: the same result every run. Used by the What-If calculator, the historical backtest, and Deterministic mortality.

DIA (Deferred Income Annuity) — An annuity you buy now with a lump sum that begins paying income at a future date you choose (unlike a SPIA, which starts right away). See Income sources.

Exclusion ratio — For a non-qualified annuity (one bought with after-tax dollars), the fraction of each payment that’s a tax-free return of your own principal. IRA/401(k)-funded annuities are fully taxable, so their exclusion ratio is 0. See Income sources.

FRA (Full Retirement Age) — The age you receive your full Social Security benefit with no early-claim reduction (67 for anyone born in 1960 or later). See Social Security.

Guardrails — A withdrawal method that holds spending steady but automatically trims it in bad markets and raises it in good ones, keeping your withdrawal rate within set bounds.

Heir tax rate — Your estimate of the ordinary rate your heirs pay on inherited Traditional and HSA balances, used only for the after-tax legacy figure (Assumptions tab; default 25%, plus an optional state rate).

IRMAA (Income-Related Monthly Adjustment Amount) — A Medicare surcharge added to your Part B and Part D premiums when your income in the prior year is high. Assessed per person. See Taxes.

Legacy — The portfolio value left at the end of your plan — what you’d pass on.

LHS (Latin Hypercube Sampling) — An efficient way the Optimizer samples a large search space with far fewer runs than a full grid. See the Optimizer overview.

MAGI (Modified Adjusted Gross Income) — The income measure used to determine IRMAA surcharges.

Medigap — Supplemental insurance that covers Medicare’s out-of-pocket gaps; you set a monthly premium per person. See Health insurance bridge.

Monte Carlo simulation — Modeling uncertainty by running thousands of randomized futures and summarizing the range of outcomes. The foundation of RetireRange. See Understanding your results.

Nominal vs. real — Nominal dollars are the actual future amounts; real dollars are adjusted to today’s purchasing power. The Results tab toggles between them.

Percentile (P10, P50, P90) — A value below which that percentage of outcomes fall. P10 is an unlucky outcome (only 10% did worse), P50 is the median, P90 is lucky. Watch P10 to judge a plan’s safety.

PIA (Primary Insurance Amount) — The Social Security benefit you’d get at your Full Retirement Age, before any early-claim reduction or delayed-claim increase.

Plan horizon / plan end age — How far out the simulation runs (e.g., to age 100). It’s a planning horizon, not a prediction of lifespan; setting it higher is more conservative.

QLAC (Qualified Longevity Annuity Contract) — A deferred income annuity held inside a Traditional IRA. Flagging an annuity as a QLAC defers the RMDs on the money used to buy it until its payments begin — a longevity-and-tax planning tool. See Income sources and RMDs.

RMD (Required Minimum Distribution) — The minimum the IRS requires you to withdraw each year from Traditional accounts once you reach RMD age (73 today, 75 for those born in 1960 or later). See RMDs.

Roth conversion — Moving money from a Traditional account to a Roth, paying tax now so future growth and withdrawals are tax-free. See Roth conversions.

Sequence-of-returns risk — The danger that a bad run of returns early in retirement permanently harms your plan, even if long-run average returns are fine. A core reason to use Monte Carlo.

Shared seeds — Running multiple strategies against the same random market sequences, so differences in outcome reflect the strategy, not luck. Powers the Compare tab.

Shortfall — A month where the plan couldn’t fully fund your spending target after drawing from every account. The rate of this is shown on the Results tab as the Income Gap Rate.

Spending phases — Modeling spending that changes through retirement (the active "go-go," slower "slow-go," and later "no-go" years) instead of one flat number.

SPIA (Single Premium Immediate Annuity) — An annuity you buy with a single lump sum that starts paying income right away. See Income sources.

SSA (Social Security Administration) — The federal agency that runs Social Security. Your SSA statement — the benefit estimate it provides free at ssa.gov — is where you’ll find the figures RetireRange asks for (your estimated benefit at 62, at Full Retirement Age, and at 70). See Social Security.

Stochastic — Random; varying according to a probability distribution (as in Stochastic mortality, which samples a death age each run).

Success rate — The share of simulated futures in which your money lasted to the end. A measure of resilience — and higher isn’t always better. See Understanding your results.

Uniform Lifetime Table — The IRS table that sets how much of a Traditional account must be withdrawn each year as an RMD, based on age.

VEBA (Voluntary Employee Benefit Account) — A tax-advantaged account reserved for medical expenses; drawn before your HSA and never used for general spending.

Volatility — How much returns swing year to year. Higher volatility widens the range of outcomes, both good and bad. See Assumptions tab.