Okla. Admin. Code § 260:40-24-2
The following words and terms, when used in this subchapter, shall have the following meaning, unless the context clearly indicates otherwise:
"Dependent" means an individual, who qualifies as a dependent under Section 125 of the Internal Revenue Code, taking into account Section 105(b) of the Internal Revenue Code.
"Health Savings Account (HSA)" means the bookkeeping account maintained by the HSA Administrator/Trustee/Custodian used for crediting contributions and accounting for benefit payments.
"HSA Administrator/Trustee/Custodian" Insured banks and credit unions are automatically qualified to handle HSAs. Any bank, credit union or any other entity that currently meets the IRS standards for being a trustee or custodian for an IRA or Archer Medical Savings Account (MSA) can be an HSA trustee or custodian. The law also allows insurance companies to be HSA trustees or custodians.
Okla. Admin. Code § 260:40-24-2