To be eligible for a Medigap plan, you must first be enrolled in Medicare Part A and Part B. Medigap policies help cover costs that Original Medicare does not, such as copayments, coinsurance, and deductibles. Here’s what you need to know about enrolling in a Medigap plan:

• Medigap Open Enrollment Period: This six-month period begins the month you turn 65 and are enrolled in Medicare Part B. During this time, you have guaranteed issue rights, meaning insurers cannot deny you coverage or charge higher premiums due to pre-existing conditions.
• Enrolling After Open Enrollment: If you miss your initial enrollment window, you may still apply for a Medigap plan, but insurers may use medical underwriting to determine your eligibility and premium rates.
• Medigap for Those Under 65: If you’re under 65 and eligible for Medicare due to a disability, your options for Medigap coverage vary by state. 
• No Coverage Overlap: Medigap policies do not work with Medicare Advantage Plans. If you have a Medicare Advantage Plan and want Medigap, you’ll need to switch back to Original Medicare.