26 U.S. Code § 401 - Qualified pension, profit-sharing, and stock bonus plans
(h) Medical, etc., benefits for retired employees and their spouses and dependentsUnder regulations prescribed by the Secretary, and subject to the provisions of section 420, a pension or annuity plan may provide for the payment of benefits for sickness, accident, hospitalization, and medical expenses of retired employees, their spouses and their dependents, but only if -
(1)
such benefits are subordinate to the retirement benefits provided by the plan,
(2)
a separate account is established and maintained for such benefits,
(3)
the employer’s contributions to such separate account are reasonable and ascertainable,
(4)
it is impossible, at any time prior to the satisfaction of all liabilities under the plan to provide such benefits, for any part of the corpus or income of such separate account to be (within the taxable year or thereafter) used for, or diverted to, any purpose other than the providing of such benefits,
(5)
notwithstanding the provisions of subsection (a)(2), upon the satisfaction of all liabilities under the plan to provide such benefits, any amount remaining in such separate account must, under the terms of the plan, be returned to the employer, and
(6)
in the case of an employee who is a key employee, a separate account is established and maintained for such benefits payable to such employee (and his spouse and dependents) and such benefits (to the extent attributable to plan years beginning after March 31, 1984, for which the employee is a key employee) are only payable to such employee (and his spouse and dependents) from such separate account.
For purposes of paragraph (6), the term “key employee” means any employee, who at any time during the plan year or any preceding plan year during which contributions were made on behalf of such employee, is or was a key employee as defined in section 416(i). In no event shall the requirements of paragraph (1) be treated as met if the aggregate actual contributions for medical benefits, when added to actual contributions for life insurance protection under the plan, exceed 25 percent of the total actual contributions to the plan (other than contributions to fund past service credits) after the date on which the account is established. For purposes of this subsection, the term “dependent” shall include any individual who is a child (as defined in section 152(f)(1)) of a retired employee who as of the end of the calendar year has not attained age 27.