HSA contributions are individual contributions. The regular limit for having family-coverage applies to both spouses contributions in aggregate, but the $1,000 catch-up limit applies to each individual separately. If both spouses are HSA-eligible and one has family HSA coverage, the family limit gets split between contributions to the HSAs of the spouses but each of the spouses who is age 55 or over can separately contribute to their own HSA an additional $1,000 (assuming full-year eligibility).
