Medical underwriting is a practice employed by private health insurers when determining if they will provide coverage to a prospective beneficiary. During the underwriting process, an applicant may be required to undergo a physical examination, and the insurer may reject the individual based on the results or the patient’s medical history.

If you enroll in a Medicare Supplement plan (also known as Medigap) during your open enrollment period, you have a “guaranteed issue right” to purchase any Medigap plan being offered in your coverage area. During this open enrollment, insurers cannot reject you or charge a higher premium based on a pre-existing health condition or disability. Insurers also cannot require you to undergo medical underwriting.

Your Medigap open enrollment period lasts six months and begins on the first day of the month you turn 65 and are enrolled in Medicare Part B. This period cannot be delayed, and, when it is over, you cannot get it again. If you decide to delay Medicare Part B coverage, your Medigap open enrollment will not start until you have Medicare Part B.

Should you decide to join a Medigap plan after the open enrollment period, you may not have guaranteed issue and may have to submit to the medical underwriting process. An insurer may also review your medical history and refuse to sell you a policy or sell you one at a higher cost, if you do not meet its underwriting requirements.

There are some exceptions where beneficiaries can enroll in a Medicare Supplement plan outside of their open enrollment with guaranteed issue. These include, but are not limited to:

  • If you were in a Medicare Advantage plan and are moving out of the plan’s coverage area, you’ll be involuntarily disenrolled from the plan. In this case, you’ll also be eligible for a Special Election Period to enroll in a different Medicare Advantage plan. You must enroll in a new Medicare Advantage plan with an effective date that starts the month after you move or at the beginning of the seventh month; otherwise, you will be automatically enrolled in Original Medicare. If you return to Original Medicare, you may have a guaranteed-issue right.
  • If your Medicare Advantage plan is leaving Medicare, and you switch back to Original Medicare.
  • If you have coverage under Original Medicare and an employer health plan, and the employer health coverage is ending.
  • If you leave your Medicare Advantage or Medigap plan because the insurance company deceived you or didn’t follow the law.
  • If your Medigap insurer goes bankrupt, or you lose coverage through no fault of your own.
  • If you join a Medicare Advantage plan and decide to switch back to Original Medicare within a year, you have a “trial right” to buy any Medigap plan.