If one of you has a "family" HSA and the other has a "self-only" HSA you can contribute to either one. Do not split them unless you actually contributed to two different plans. If one spouse has a family plan and the other self you indicate a family plan for both. But contribution is still limited to the normal amounts.
Enter 'family' if your HSA plan was a family plan. An HSA is a family plan if it covers anyone in addition to yourself. One spouse does not have to be included for it to be a family plan.
For 2016, the maximum contribution to an HSA is $3,350 for an individual plan or $6,750 for a family plan. This is the combined contribution from both you and your employer. If you're 55 or older, you're allowed to contribute up to $1,000 more for a maximum of $4,350 (individual) or $7,750 (family).
(Edited: 03.30.2017 | 8:01a PST)
