Tax-free treatment of funds
Transfers of HSA funds incident to divorce are generally not considered taxable distributions, as long as they're made as part of a divorce or separation instrument. Your spouse still gets the tax-free treatment of HSA assets, both during the transfer and afterward, when withdrawing for qualified medical expenses.
How to request the transfer
Contact your administrator to request a transfer of funds to your spouse's name. You'll need to provide your divorce decree, and the funds will be split as executed in the decree.
HSA rules still apply
Outside of the transfer rules above, all of the same rules apply:
You can't use your HSA to cover your ex-spouse's medical expenses.
To make new or additional contributions to an HSA, you must be HSA-eligible. This is true for an ex-spouse receiving transferred funds as part of a divorce, too.
Dependent status of children
A child of parents who are divorced, separated, or living apart for the last six months of the calendar year is treated as the dependent of both parents, even if the custodial parent releases the claim to the child's tax exemption.
Source: IRS Publication 969, Health Savings Accounts and Other Tax-Favored Health Plans