rmd-uniform-lifetime

IRS Required Minimum Distribution (RMD) math — the Uniform Lifetime Table and Single Life Table from Publication 590-B (2022+), plus the SECURE 2.0 required-beginning-age logic. Zero dependencies.

npm install rmd-uniform-lifetime

Why

Everyone with a traditional IRA or 401(k) eventually has to take RMDs, and the math is exact: prior-year-end balance ÷ an age-based divisor from an official IRS table. The tables were revised for 2022 and SECURE 2.0 moved the starting age from 72 to 73 (and to 75 in 2033) — a combination that trips up older code. npm had no package with the current tables. This one has them, verified against the IRS's own worked example.

import { rmdUniformLifetime, requiredBeginningAge } from "rmd-uniform-lifetime";

// IRS Pub 590-B example: $100,000 at age 75 → $4,065
rmdUniformLifetime(100_000, 75);   // 4065.04

requiredBeginningAge(1955);        // 73  (SECURE 2.0)
requiredBeginningAge(1965);        // 75

API

• rmdUniformLifetime(priorYearEndBalance, age) — an owner's RMD (Table III).
• rmdSingleLife(priorYearEndBalance, age, subtractYears?) — a beneficiary's RMD (Table I); pass subtractYears for the fixed-divisor "stretch" reduction.
• rmd(balance, divisor) — the primitive; use it with a Joint & Last Survivor divisor (Table II) when the sole beneficiary is a spouse more than 10 years younger.
• uniformLifetimeDivisor(age) / singleLifeDivisor(age) — raw table lookups (ages past 120 use the age-120 value).
• requiredBeginningAge(birthYear) → 72 | 73 | 75 per SECURE 2.0.
• isRmdRequired(birthYear, distributionYear) — whether an RMD is due that year.
• UNIFORM_LIFETIME_TABLE / SINGLE_LIFE_TABLE — the exported tables.

Scope

Ships the Uniform Lifetime Table (owners) and Single Life Table (beneficiaries) in full. The Joint & Last Survivor Table (Table II) is a large two-dimensional grid indexed by both spouses' ages; rather than risk a transcription error, look up that divisor from IRS Table II and pass it to rmd(balance, divisor). The RMD itself may be deferred to April 1 of the year after the required beginning age, with two distributions then due — the package computes the amount; the April-1 timing is the account holder's to apply. Not tax advice.

Related

By the same author, a US finance toolkit: tips-index-ratio · treasury-fiscaldata · tbill · instrument-identifiers · 32nds.

Author

Built by Moshe Malka — engineering leader in New York City. Studio work at Quentin.Code.

MIT © Moshe Malka