Generally, you may contribute to an HSA if you’re enrolled in Medical Plan Option C, but there are a few exceptions. You can’t contribute to an HSA if:

• You’re covered under any other medical plan that’s not a high-deductible plan, including Medical Plan Option A or B, Medicare or Tricare.
• Any of your eligible health care dependents has a Health Care Flexible Spending Account (HCFSA).
• You’re a dependent on anyone else’s tax return.