Medicare and contributions to HSA

My husband is enrolled in an HSA with family coverage.  He makes contributions to the maximum for family coverage.  His employer (with more than 20 employees) makes contributions to this account on his AND my behalf.  I do not work but am now 66.  My understanding is that I cannot enroll in either part A or B of Medicare as long as my husband and his employer continue to make these contributions.  If his employer did not make the contributions to his account on my behalf only, does that change the answer?  Meaning, could he still max out on family coverage and receive the additional amount of employer contribution for only his behalf if I then enroll in either Medicare part A or B?