HSA: Same plan as wife; how to contribute

[martyconlonontherun]

In prior years, my wife and i had separate HSA accounts. We each would contribute the max. This year we are covered by her plan but they won't let her contribute the full 7k through payroll.

How do I contribute the remaining 3.5k? Does it matter which account her current one with the insurance plan or my account from prior year with no current plan? Are there tax implications?

[MDM]

See Publication 969 for details.

In short, as far as the IRS is concerned a couple may decide between themselves how to split the $7K maximum family contribution.  Your wife's employer may have more stringent restrictions for payroll deduction, but she or you may always make contributions direct to your respective HSAs.

The non-payroll contributions don't avoid FICA tax, but are deductible when you file.