Required Beginning Date (RBD)

A required beginning date is the specific calendar date by which a retirement account owner must take their first required minimum distribution. For an IRA owner, and for anyone who owns more than 5% of the employer sponsoring a workplace plan, it is April 1 of the calendar year following the year they reach the applicable age set by statute. For other participants in a workplace plan, it is April 1 of the year following the later of the year they reach that age or the year they retire. The definition sits at section 401(a)(9)(C), with the applicable age itself defined at 401(a)(9)(C)(v).

Two things about that structure do most of the practical damage. First, the RBD is a date, not an age — so "when do RMDs start" and "when is my RBD" have different answers, and the gap between them is up to fifteen months. Second, because the date falls in the year after the trigger year, a person who waits until the last possible day takes their first and second required minimum distributions inside the same tax year. The amount of each distribution is a separate question that belongs to the required minimum distribution rules; the RBD only fixes the deadline.

The applicable age, and one genuine ambiguity. The age that triggers the RBD was raised by the SECURE 2.0 Act and is scheduled to rise again for a later birth cohort. The statute sets it two ways: 73 for someone who attains 72 after 2022 and 73 before 2033, and 75 for someone who attains 74 after 2032. Read literally, those two tests overlap for exactly one birth year — a person born in 1959 satisfies both, and so has two applicable ages. That is a drafting error rather than a policy, and the position today is genuinely unresolved: Treasury's July 2024 final regulations pointedly reserve the paragraph covering that cohort, while proposed regulations issued the same day would settle it at 73. Proposed regulations are not law. Anyone born in 1959 therefore has a question with a strong indication but no final answer, which is worth knowing rather than guessing at — and worth confirming against current IRS guidance before acting.

The still-working exception is narrower than it sounds. It postpones the RBD to April 1 following the year of retirement, and it applies only to the plan of the employer you are still working for. It does not reach a traditional IRA, a SEP IRA, or a SIMPLE IRA — those follow the age-based date regardless of employment — and it does not reach a former employer's 401(k) you left behind, which follows the age-based date even while you keep working somewhere else. There is a mechanism for that last one: if the current employer's plan accepts incoming rollovers, consolidating the old balance into it before the applicable age brings that money under the exception, whereas leaving it where it sits does not. It is also a plan option, so a plan may require distributions at the age-based date anyway. And it is unavailable to a 5-percent owner, which for this purpose means someone owning more than 5% of the stock or of the capital or profits interest in the sponsoring business. An owner-employee who keeps working past the applicable age still has an age-based RBD.

Roth accounts sit outside the whole framework. A Roth IRA owner never has a required beginning date, because Roth IRAs carry no lifetime required distributions. Designated Roth accounts inside a 401(k), 403(b), or governmental 457(b) were freed from pre-death required distributions by SECURE 2.0 for years beginning after 2023 — though pre-death Roth distributions genuinely were required for 2022 and 2023, which matters when reconstructing an older account history.

The reason beneficiaries care. The RBD does double duty: it is the owner's deadline, and it is also the switch that decides what a beneficiary owes after the owner dies. Where a beneficiary is subject to the 10-year rule, annual distributions in years one through nine are required only if the owner died on or after their required beginning date. That test is frequently paraphrased as "whether the owner had started taking RMDs," which is not the same event — someone can have taken a voluntary withdrawal without having reached their RBD, and someone can reach their RBD in a year they take nothing because the grace period is still running. Because Roth owners never have an RBD, they are always treated as dying before it, so the annual-distribution overlay never reaches an inherited Roth IRA.

The sequence: you reach the applicable age in some year — call it year one — and a required minimum distribution for year one is now owed. Your RBD is April 1 of year two. You may take the year-one distribution any time from January of year one through that date. The year-two distribution, however, is still due by December 31 of year two, on its own schedule. Every distribution after the first is a December 31 deadline; only the first one gets the April 1 grace period.

A hypothetical example. Marcus reaches the applicable age in year one, and his required minimum distribution for that year works out to $18,000. He decides to use the grace period, so he takes nothing in year one and withdraws the $18,000 in March of year two. But his year-two distribution — say $19,000, because the balance and the life-expectancy factor both changed — is still due by December 31 of year two. Both land on the same tax return: $18,000 + $19,000 = $37,000 of ordinary income in one year, instead of $18,000 in year one and $19,000 in year two.

Whether that matters depends entirely on the brackets involved. Bunching $37,000 of income into one year can push a retiree into a higher marginal rate, increase the taxable share of Social Security benefits, and — with a two-year lag — raise Medicare premium surcharges. It can also cut the other way for someone with an unusually low-income year two. The grace period is a choice with a tax consequence, not free flexibility.

Pros

• The first-year grace period gives real flexibility to someone who retires mid-year or whose income is unusually high in the trigger year.
• The still-working exception lets a workplace-plan participant who has not retired keep deferring, which can be worth a great deal to someone working into their seventies.
• The date is mechanical and knowable years in advance, so it can be planned around rather than reacted to.

Cons

• Using the full grace period stacks two distributions into one tax year, and the second-year distribution cannot be moved to compensate.
• The still-working exception is easy to over-read: it never applies to IRAs, never to a former employer's plan, and never to a more-than-5% owner.
• It is a deadline with teeth — a missed required distribution carries an excise tax on the shortfall.
• The applicable age has moved twice in recent years and is scheduled to move again, so older guidance and even a person's own earlier planning can be out of date.