In a recently issued FAQ, the Centers for Medicare and Medicaid Services stated that effective in 2015, health insurers must allow spouse to be defined to include both same and opposite-sex couples.  Insurers are encouraged to comply with this requirement earlier.  This does not dictate how employers define its dependent eligibility provision in their group health insurance plans.  What it does is require an insurer to allow an employer to define spouse to include both same and opposite-sex couples.  Employers should also be aware of sexual orientation discrimination rules that may impact how spouse is defined.  Employers with questions about these matters should consult with their legal counsel.