29 CFR § 825.211 - Maintenance of benefits under multi-employer health plans.
(a) A multi-employer health plan is a plan to which more than one employer is required to contribute, and which is maintained pursuant to one or more collective bargaining agreements between employee organization(s) and the employers.
(b) An employer under a multi-employer plan must continue to make contributions on behalf of an employee using FMLA leave as though the employee had been continuously employed, unless the plan contains an explicit FMLA provision for maintaining coverage such as through pooled contributions by all employers party to the plan.
(c) During the duration of an employee's FMLA leave, coverage by the group health plan, and benefits provided pursuant to the plan, must be maintained at the level of coverage and benefits which were applicable to the employee at the time FMLA leave commenced.
(1) The employee's FMLA leave entitlement is exhausted;
(3) The employee provides unequivocal notice of intent not to return to work.