Seniors become eligible for Medicare at age 65, according to the National Council on Aging. The enrollment process usually begins by contacting the Social Security Administration, either online, in person or via telephone. Those who are already receiving Social Security Disability are automatically enrolled when eligible.
The initial enrollment period for Medicare is the seven-month period around the individual's 65th birthday, three months before and three months after, explains AARP. Seniors working past age 65 with employee health coverage are entitled to a special enrollment period that lasts eight months from either the start of retirement or the loss of health care, whichever comes first.