Understanding Medicare, Simplified
Medicare has rules. Here's what you actually need to know, without the jargon.
The Parts of Medicare
Four parts, each covering something different. Most people combine them into one of two paths: Original Medicare plus Medigap plus Part D, or a single Medicare Advantage plan that bundles everything together.
Part A — Hospital
Inpatient hospital stays, skilled nursing care, hospice, and some home health services.
Premium-free for most people who worked 10+ years and paid Medicare taxes.
Part B — Medical
Doctor visits, outpatient care, preventive services, and durable medical equipment.
Standard monthly premium applies. Income-based adjustments (IRMAA) kick in at higher income tiers.
Part C — Medicare Advantage
A private-plan alternative to Original Medicare that bundles Parts A and B — and usually Part D — into one plan.
Premiums vary by plan and region. Many plans bundle extras like dental, vision, and hearing.
Part D — Prescription Drugs
Standalone drug coverage you add to Original Medicare, or coverage built into a Medicare Advantage plan.
Premiums vary by plan. A late-enrollment penalty applies if you delay without creditable drug coverage.
Enrollment Periods
Medicare is rules-based. Missing the right window can mean lifetime penalties. Here are the four windows that matter most.
Initial Enrollment Period (IEP)
A 7-month window around your 65th birthday: the three months before, the month of, and the three months after. For most people, this is the first chance to enroll in Medicare.
Annual Enrollment Period (AEP)
October 15 – December 7 each year. Change Medicare Advantage or Part D plans for the next calendar year. Changes take effect January 1.
Special Enrollment Period (SEP)
Triggered by qualifying life events like moving to a new area, losing employer coverage, or becoming eligible for Extra Help. Windows and rules vary by event.
Medigap Open Enrollment Period
A one-time 6-month window that starts the month you're both 65 and enrolled in Part B. During this window, insurers cannot deny Medigap coverage or charge more based on health history.
Timing Matters — Penalty Warnings
Part B Late-Enrollment Penalty
If you don't sign up for Part B when first eligible and don't have other creditable coverage, your premium can go up 10% for each full 12-month period you could have had it — for as long as you have Part B.
Estimate your Part B penaltyPart D Late-Enrollment Penalty
If you go 63+ continuous days without creditable drug coverage after your IEP, a permanent surcharge is added to your Part D premium — 1% of the national base premium for every month you went without.
Estimate your Part D penaltyHow to Apply for Medicare
You can sign up for Medicare directly through Social Security — by phone, online, or in person — or have a licensed advisor walk you through the timing and trade-offs first.
Online via Social Security
Apply for Original Medicare in 10–15 minutes at the official SSA website.
By Phone with Social Security
Speak with an SSA representative to apply, ask questions, or update your record.
By Phone with Medicare
For Medicare-specific questions about Parts A, B, C, D, plans, or claims.
At Your Local Social Security Office
Find your nearest office to apply or pick up paperwork in person.
With a Licensed AdviseCare Advisor
If you want a person to walk you through the timing, the parts, and the trade-offs before you apply, we'll help — at no cost.
Some common situations
- Working past 65 with employer coverage? How employer coverage works with Medicare →
- Have VA benefits? VA benefits and Medicare Advantage →
- Choosing between Medicare Advantage and Medigap? Compare both side by side →
Explore Further
Keep going. These pages go deeper on the topics most people ask about next.