Missouri Revised Statutes Title XXXI. Trusts and Estates of Decedents and Persons Under Disability § 456.006. Health savings account, trust may be created, when

1. Where a trust or custodial account constitutes a health savings account, as defined under 26 U.S.C. Section 223(d)(1),  1 a trust may be created by any of the following:

2. In any case, a trust or custodial account shall be deemed to have been established on the first day on which the individual who is the beneficiary of such trust or custodial account is an eligible individual, as defined under 26 U.S.C. Section 223(c)(1), in that calendar year in which such trust or custodial account is created in accordance with this section.