Medicare Supplement, or Medigap, coverage is only supplemental to what Medicare covers. If you have expenses not covered in the first place by Medicare (such as non-essential cosmetic surgery), your Medicare Supplement policy generally won’t pay for the coinsurance or deductible. Also, as a general rule, Medigap policies do not cover custodial care or long-term nursing home or home care. *Note: The terms Medicare supplement and Medigap can be used interchangeably.