In this section the following words having the meanings indicated. “Health savings account” has the meaning stated in § 223 of the Internal Revenue Code. “High deductible health plan” has the meaning stated in § 223 of the Internal Revenue Code. A health savings account is established on the first day that an individual becomes covered by a high deductible health plan. The health savings account shall be opened with a trustee or custodian within the time period prescribed by law, without extensions, for filing a federal income tax return for the year in which the health savings account is established. A health savings account is established regardless of a transfer of cash or other property to the account and, unless required by the trustee or custodian, it is not necessary for any party to sign a health savings account trust or custodial agreement regarding the health savings account.