The term is used by a beneficiary to cover healthcare services that are not covered by Part A or B. These policies must meet federally imposed standards and are offered by Blue Cross and Blue Shield and various other commercial health insurance companies.

The medical healthcare services which are used by persons who are beneficiary and get healthcare services which costs do not cover by person and instead of that private companies will pay his/her cost this term is known as medigap.

Medigap is also known as medicare supplement insurance which cover the costs of medical treatment of a person that original medicare does not cover. Mainly it is covered by private companies like Blue Cross and Blue Shield and their policies must be according to federally imposed standards.