What is the purpose of Medicare form CMS-40B?

Seniors use Medicare Form CMS-40B to apply for Medicare Part B medical insurance, reports the Social Security Administration. Seniors eligible to receive Medicare Part A hospital insurance without paying premiums use Form CMS-40B, while seniors who only want to enroll in Medicare Part B use a different form. Once seniors complete the form, they mail it or deliver it in person to the local Social Security office.

Seniors use Form CMS-40B if they did not sign up for optional Medicare Part B supplementary medical insurance on their initial Medicare applications, if they turned down Medicare Part B after automatic enrollment, if they terminated Medicare Part B after initially enrolling in it or if they lost Medicare Part B coverage because they did not pay the premiums, explains the SSA. Once seniors miss their initial enrollment periods for Medicare Part B or terminate their coverage for any reason, they can only submit Form CMS-40B to initiate or renew coverage during specified yearly enrollment periods.

People who pay Medicare taxes while working receive premium-free Medicare Part A hospital insurance, according to Medicare.gov. However, everyone must pay monthly premiums for Medicare Part B supplementary medical insurance. Although most people make standard premium payments, people whose modified adjusted gross incomes are above a stipulated amount pay more.