26 CFR 31.3401(a)(19)-1: (a)(19)-1 Reimbursements under a self-insured medical reimbursement plan.

Amounts reimbursed to or on behalf of an employee after December 31, 1979, as a medical care reimbursement under a self-insured medical reimbursement plan (within the meaning of section 105(h)(6)) do not constitute wages and hence are not subject to withholding even though such reimbursement is includible in the gross income of an employee. For rules with respect to self-insured medical reimbursement plans, see section 105(h) and § 1.105-11 of this Chapter (Income Tax Regulations).