When Can I Sign Up For Medigap Insurance? 
There is an `` open enrollment period '' during which you can buy any Medigap insurance policy -LRB- Plan F -RRB- sold in your state beginning the month in which you turn age 65 and you are enrolled in Medicare Part B . During this six month open enrollment period , you can buy any Medigap insurance offered , even if you have health problems , for the same price as people in good health . If you apply for Medigap coverage after your open enrollment period , there 's no guarantee that an insurance company will sell you a Medigap policy if you dont meet the medical underwriting requirements , unless you 're eligible because you have group health insurance through an employer or union . If this is your situation , the Medigap enrollment period begins when you sign-up for Part B . There are some situations if you are under 65 and are eligible for Medicare because of a disability you could be eligible for Medigap coverage . If you have End-Stage Renal Disease -LRB- ESRD -RRB- and are under 65 , some states require at least one type of Medigap policy to be offered to you . 