when you enter his w-2 did you ever get to the question did any of the HSA contributions go into your spouse's account? must be answered yes. for his a/c enter 0 for your's enter 1500
in the HSA section. HSA for spouse should be checked
then enter the 5600 you made personally
make sure you answer yes to having a HDHP (even if through your husband)
make sure you answer you had a family plan every month of the year (the law says if either had family coverage you both had family coverage)
when it asks about your husbands HDHP coverage select family
click continue as needed to finish with HSA no amounts should be enter for him
you may end up with one 8889 for you and one for him - his should have no amounts other than possibly 0's
most likely you answered none to the question of being covered by an HDHP for the year
