You're Turning 65. How Do You Enroll in Medicare?

You are turning 65 — or already have. Medicare enrollment is one of the most consequential and confusing healthcare decisions you will make. The options are genuinely complex, the deadlines are strict, and the penalties for missing them are permanent.

The good news: once you understand the four parts and the two paths, the decision becomes manageable.

Part A (Hospital Insurance): Covers inpatient hospital stays, skilled nursing facility care, hospice. Premium-free for most people (if you or your spouse paid Medicare taxes for 10+ years). Enroll automatically if receiving Social Security.

Part B (Medical Insurance): Covers doctor visits, outpatient care, medical equipment, preventive services. Standard monthly premium: $185/month (2025), higher for high earners. You must actively enroll.

Part C (Medicare Advantage): An alternative to Original Medicare (A + B). Run by private insurers, these plans bundle A + B + often D (prescriptions) + extras (dental, vision, hearing). Monthly premiums can be $0 but networks are limited. You cannot use Medigap with Advantage plans.

Part D (Prescription Drug Coverage): Covers prescription medications. Offered through private plans. Monthly premium: $15-$100+ depending on the plan and your drugs. You need this unless your Part C plan includes prescription coverage.

Path 1 — Original Medicare + Medigap + Part D - Parts A + B cover 80% of approved costs. You pay the remaining 20% (no cap). - A Medigap (Medicare Supplement) plan covers most or all of the 20% gap. - Part D covers prescriptions separately. - Pros: See any doctor who accepts Medicare (nearly all do), no network restrictions, predictable costs with Medigap. - Cons: Three separate premiums (B + Medigap + D). Medigap premiums are $100-$300/month.

Path 2 — Medicare Advantage (Part C) - One plan replaces Parts A, B, and usually D. - Monthly premium is often $0-$50 (in addition to Part B premium). - Includes extras (dental, vision, gym membership). - Pros: Lower monthly premiums, bundled coverage, extras. - Cons: Network restrictions (HMO/PPO), prior authorization for procedures, out-of-pocket maximum can reach $8,000-$12,000/year.

How to choose: If you value provider choice and predictable costs, choose Original + Medigap. If you are healthy, want lower premiums, and are comfortable with a network, Medicare Advantage can work. Review your specific doctors and prescriptions before choosing.

Initial Enrollment Period (IEP): 7-month window centered on your 65th birthday month (3 months before + birth month + 3 months after). Missing this window for Part B triggers a 10% per-year permanent premium penalty.

If you are still working at 65: You can delay Part B enrollment if you have credible employer coverage (from an employer with 20+ employees). When you leave the job or lose coverage, you get a Special Enrollment Period (8 months). You must enroll within this window to avoid penalties.

Open Enrollment (October 15 - December 7): Annual window to switch Medicare Advantage plans, switch between Original and Advantage, or change Part D plans. Review your coverage annually — plans change terms every year.