The five categories, precisely. In statutory order they are: (I) the surviving spouse of the account owner; (II) a child of the owner who has not reached majority; (III) an individual who is disabled within the meaning of section 72(m)(7); (IV) an individual who is chronically ill within the meaning of section 7702B(c)(2); and (V) any individual who is not more than ten years younger than the owner.
Categories (III) and (IV) are routinely collapsed into a single "disabled or chronically ill under 7702B(c)(2)" — and that is a real error worth being careful about, because 7702B(c)(2) is the long-term-care definition of chronically ill, while disabled has its own and much stricter test at 72(m)(7). Two categories, two tests, two sets of documentation, and a beneficiary who qualifies under one may not qualify under the other.
Disabled, under 72(m)(7), means unable to engage in any substantial gainful activity by reason of a medically determinable physical or mental impairment that can be expected to result in death or to be of long-continued and indefinite duration. Three details do most of the work. The "substantial gainful activity" measured is the activity the person customarily engaged in before the impairment arose, not any work at all. An impairment that can be remedied with reasonable effort is not a disability for this purpose. And the test is different for a beneficiary under 18, who instead must have marked and severe functional limitations. A Social Security disability determination in force at the owner's death is the practical safe harbor for an adult.
Chronically ill, under 7702B(c)(2), means certified by a licensed health care practitioner as unable to perform at least two activities of daily living — eating, toileting, transferring, bathing, dressing, continence — without substantial assistance, or as requiring substantial supervision because of severe cognitive impairment. For eligible-designated-beneficiary purposes the statute modifies that definition in a way most summaries omit: the long-term-care world's 90-day threshold is replaced by a certification that the inability is indefinite and reasonably expected to be lengthy in nature. That makes the retirement-account test stricter than the one in a typical long-term-care policy, so a certification written for an insurance claim does not automatically carry over.
The documentation deadline is the part that actually goes wrong. For both categories, documentation of the beneficiary's status has to reach the plan administrator or custodian by October 31 of the calendar year following the year of the owner's death. Miss it and the beneficiary can be administered as an ordinary designated beneficiary under the 10-year rule despite qualifying, which is a paperwork failure with a decades-long consequence.
The two categories people most often misread. Category (II) says child of the employee — so a grandchild does not qualify simply by being a minor, and neither does a niece, nephew, or minor sibling. And its relief is temporary rather than permanent: a minor child takes life-expectancy distributions only until they reach majority, which the final regulations set at age 21 for this purpose, overriding whatever the state-law age of majority happens to be. At that point the 10-year rule takes over, with the twist that the formerly-minor child keeps taking annual distributions through the window regardless of the owner's required beginning date. Category (V) — "not more than ten years younger" — is the one that catches people by surprise in the other direction, because it quietly makes most siblings, and many partners and close friends, eligible. A sibling eight years younger is an EDB; a sibling twelve years younger is not.
Where the status ends. An EDB's own death does not pass eligibility along. The successor beneficiary who inherits from an EDB falls under the 10-year rule, measured from the EDB's death — so a surviving spouse who stretches for twenty years leaves their own beneficiary a ten-year deadline. Separately, the SECURE 2.0 Act added relief for certain applicable multi-beneficiary trusts created for disabled or chronically ill beneficiaries, which allows a trust structure to preserve the extended payout for that beneficiary where a conventional trust arrangement would not have.
A surviving spouse is more than an EDB. Spousal status carries options no other category gets, including treating the inherited IRA as the survivor's own account. Those choices belong to the inherited IRA rules; what matters here is simply that a spouse never has to rely on the ten-year window.