HSAs are the property of only one tax payer. IRS regulations do not permit transfers from one taxpayer to another under normal circumstances. Publication 504 does address the issue of HSA transfer (full or patial) in divorce situations.  The IRS guidelines described below require legal documentation (an “instrument”) for a custodian to move money from one HSA to another.

From IRS Publication 504:

 ”Health savings account (HSA). If you transfer your interest in an HSA to your spouse or former spouse under a divorce or separation instrument, it is not considered a taxable transfer. After the transfer, the interest is treated as your spouse’s HSA.”