Medicare is generous — but its enrollment rules are rigid, and several of its penalties last for life. These are the five mistakes licensed agents see most often, and how to avoid every one of them.
1. Missing your Initial Enrollment Period
You get seven months around your 65th birthday (three before your birthday month, your birthday month, and three after). Miss it without qualifying coverage and Part B carries a 10% premium penalty for every 12 months you delayed — forever.
2. Assuming COBRA or retiree coverage counts
It usually does not. Only coverage from active employment (yours or a spouse's, generally at an employer with 20+ employees) lets you delay Part B penalty-free. COBRA feels like employer insurance but does not protect you from the penalty clock.
3. Ignoring Part D because you take no medications
Healthy 65-year-olds skip drug coverage, then need it at 72 — and pay a penalty of 1% of the national base premium for every month they went without creditable drug coverage. A low-cost Part D plan at enrollment is cheap insurance against a permanent surcharge.
4. Choosing a Medicare Advantage plan without checking networks
$0-premium Advantage plans can be excellent value — but they are network products. Before enrolling, verify your doctors, your hospital, and your prescriptions are covered. The plan that is perfect for your neighbor may not include your oncologist.
5. Missing the one-time Medigap guarantee
In most states, your six-month Medigap open enrollment (starting when Part B begins) is the only time insurers must sell you a supplement regardless of health. Develop a condition later and switch plans, and you can be declined or rated up. If you want Medigap, the window to get it cleanly is early.
Get it right the first time
Every situation — working past 65, HSA contributions, snowbirding between states — has its own rules. A conversation with a licensed agent who compares all plans in your area costs nothing and routinely prevents four-figure mistakes.