Understanding Medicare, let alone signing up for it can be a daunting experience for anyone, even for the most seasoned healthcare professional. It’s complicated, and the answer to your question, whether or not you need to enroll when you turn 65, is dependent on a few different factors.

I turned to Medicare expert Diane J. Omdahl, RN, MS, whose company, 65 Incorporated, advises those turning 65 to make informed decisions about Medicare, to weigh in. Here's her explanation:

“Those turning 65 should never, ever ignore Medicare because in many cases, enrollment is necessary. However, it’s important to look at an individual’s situation to figure out the best solution and whether Medicare enrollment is an immediate necessity. If an individual is part of a group health plan through an employer with 20 or more employers, it is not necessary to enroll in Medicare. However, Medicare recommends enrollment in Part A, hospital insurance. Part A is free for those who qualify (if the individual or his or her spouse has worked and paid Medicare taxes for at least 10 years).”

She added: ”If however, the company has fewer than 20 employees (and is not part of a multi-group plan), the individual should check with the benefits administrator because the company plan can exclude Medicare-eligible employees, making Medicare a must. Even if the company plan does include Medicare-eligible individuals, enrollment in Medicare Parts A and B (Medical insurance/Doctor's visits) will still be necessary because Medicare will be the primary insurer and the company coverage will be secondary to Medicare."

Bottom Line? If you’re employed by a small company be sure to sign up on time, because not doing so will result in a late enrollment fee and paying more for medicare the rest of your life. That would be a costly error to make.