May HSA funds be commingled in a common trust fund or common investment fund?
A-66. Section 223(d)(1)(D) states that the HSA trust assets may not be commingled except in a common trust fund or common investment fund. Thus, individual accounts maintained on behalf of individual HSA account beneficiaries may be held in a common trust fund or common investment fund. A “common trust fund” is defined in Treas. Reg. ยง 1.408-2(b)(5)(ii). A “common investment fund” is defined in section 584(a)(1).
