The Short Version
Medicare has four parts, and each one does a different job. Parts A and B make up Original Medicare, which pays for hospital and doctor care. Part C, called Medicare Advantage, bundles that coverage into one private plan. Part D covers drugs, and Medigap helps pay the share Original Medicare leaves to you.
What Does Part a Cover?
Part A is hospital insurance. It pays for care you get once a hospital admits you as an inpatient.
Covered care includes:
- Inpatient hospital stays, including the room, nursing, and meals.
- Skilled nursing facility care after a qualifying hospital stay.
- Hospice care when a doctor certifies a terminal illness.
- Some home health visits ordered by your doctor.
Who Pays No Premium for Part A?
Most people pay nothing each month for Part A. If you or a spouse worked at least ten years, which is forty quarters, and paid Medicare taxes, Part A has no premium. You can confirm your work credits with Social Security at ssa.gov. Part A still has a deductible for each benefit period, so no premium does not mean no cost.
What Does Part B Cover?
Part B is medical insurance. It pays for the care you get without being admitted.
That includes doctor visits, lab work, outpatient surgery, and most preventive screenings. It also covers durable medical equipment, such as walkers, oxygen, and blood sugar monitors. Part B pays its share after you meet a yearly deductible, and you usually owe part of the rest.
Almost everyone pays a monthly premium for Part B. The amount is set each year, so check the current figure at medicare.gov before you plan a budget.
Who Pays IRMAA?
IRMAA stands for the income-related monthly adjustment amount. Higher earners pay an extra monthly amount on top of the standard Part B premium, and on Part D too.
Social Security looks at your tax return from two years back. If your income has since dropped because you retired, sold a business, or lost a spouse, you can ask for a review. File Form SSA-44 and bring proof of the change.
What Is Part C, or Medicare Advantage?
Medicare Advantage is a private plan that becomes your way of getting Parts A and B. You stay in Medicare, but the plan manages your care and sets your copays.
Most of these plans fold in drug coverage. Many add dental, vision, hearing, and fitness benefits. In exchange, you use a network, and bigger services often need prior approval.
You will see three common types:
- HMO plans, which keep care inside a set network.
- PPO plans, which cost more out of network but allow it.
- Special Needs Plans, built for people with certain conditions or with Medi-Cal.
Our guide to Original Medicare versus Medicare Advantage sets the trade-offs side by side.
How Does Part D Work?
Part D pays for prescription drugs. You can buy it on its own next to Original Medicare, or get it built into an Advantage plan.
Every plan publishes a formulary, which is its list of covered drugs. Each drug sits on a tier, and the tier drives your copay. Two plans with the same premium can treat your prescriptions very differently.
So compare by drug list, not by premium alone. Bring your exact medications, your doses, and your pharmacy. Our Part D overview explains tiers, the yearly limit on what you pay, and the penalty for signing up late.
What Does Medigap Add?
Medigap, also called Medicare Supplement Insurance, pairs only with Original Medicare. It pays part or all of the deductibles, copays, and coinsurance that Parts A and B leave to you.
The plans are standardized and labeled with letters. A Plan G from one carrier covers the same services as a Plan G from another. What changes is the premium, the rate history, and the service you get on the phone.
Medigap does not include drug coverage, so you add a Part D plan beside it. See our Medigap section for how the letters compare.
Which Path Should You Choose?
You are really choosing between two setups:
- Original Medicare, plus a Medigap plan, plus a standalone Part D plan.
- One Medicare Advantage plan with drug coverage built in.
The first setup costs more each month and leaves less to chance at the doctor. Any provider who takes Medicare will take it, which suits frequent travelers. The second costs less up front and adds extra benefits, but ties you to a network.
Three questions usually settle it:
- Do your doctors and your hospital matter more than your monthly premium?
- Do you travel, or live part of the year outside California?
- Do your prescriptions need one specific formulary?
When Do You Sign Up?
Your Initial Enrollment Period is a seven-month window. It opens three months before the month you turn 65, includes that month, and runs three months after.
Sign up in the first three months and coverage starts the month you turn 65. Wait until later in the window and the start date slides.
Two exceptions come up often:
- Still working with solid group coverage? You may delay Part B, then use a Special Enrollment Period when the job coverage ends.
- Already drawing Social Security? You are usually enrolled in Parts A and B without doing anything.
Our turning 65 page lays out the timeline month by month.
Working with Our Team
Harmony SoCal Insurance Services is an independent agency in Orange, serving Orange County since 1987. We serve neighbors across Orange County, from Anaheim and Santa Ana to Irvine, Fullerton, and Huntington Beach.
A licensed agent will review your doctors, your drugs, and your travel, then show you what fits. We represent many carriers, though not every plan in the area. Plan benefits and availability change each year, so a yearly check matters. Our help costs you nothing, and staff speak English and Spanish.
Call (714) 922-0043 or reach us through our contact page to set up a review.