Let me start by pointing out that medicare.gov is a very useful resource when trying to understand medicare. It is after all the government website for medicare. The government agency that administers medicare is the Center for Medicare and Medicaid Services, which for some reason is abbreviated as CMS.
In terms of costs, go to the cost at at glance section:
https://www.medicare.gov/your-medicare-costs/costs-at-a-glance/costs-at-glance.htmlThe quick run down:
Part A: Hospital Insurance (you'll get this automatically at age 65 is you paid into social security)
- Generally, premiums were covered by paying FICA taxes while working, so no additional premium is required
- Covers care at a hospital and skilled nursing facilities (think short term post hospitalization rehab)
- Deductible is per hospitalization (coverage period), current is $1228
- Additional co-pays (currently $322 per day) kick in after 60 days of care.
- All deductibles and co-pays are set annually by CMS
Part B: Medical Insurance (you have to sign up for this and generally become eligible at age 65)
- Current base premium is $104.90 per month (this is automatically deducted from social security payments)
- Premiums are income dependent, but don't increase much with income (~50% increase at the top)
- Covers doctors visits, tests, some preventive care, and durable medical equipment (think beds and oxygen tanks)
- Current annual deductible of $166
- Co-insurance of 20% of medicare dictated prices for eligible services (it's a little more complicated than this, but that's the gist of it)
-Deductibles and premiums are set annually by CMS, co-insurance rate is fixed at 20%
Part C: Medicare Advantage (privately administered replacement for medicare, think Humana)
- Cost structures can be completely different, but must be at a minimum "actuarily equivalent" to parts A and B
- May have additional premiums
- Still have to pay normal medicare premiums
Part D: Prescription Drug Insurance
- CMS sets minimum standards and rates plans as different levels of coverage
- Plans are privately administered and change annually even if the name of the plan is the same
- Best advice is to use the plan finder tool for your zip code and drug list at
https://www.medicare.gov/part-d/Medigap aka Medicare Supplement Insurance:
- Letter codes (A to K I think) dictate plan coverage details as set out by CMS
- Privately administered plans that add additional coverage on top (instead of replacing) regular medicare parts A and B
- Have additional premiums
- Cover medicare costs such as co-pays, deductibles, and co-insurance
- The only part of coverage than can change after issue is the monthly premium
- Require underwriting (i.e. are you healthy enough) unless issued when you become eligible for medicare (i.e. the first three months after you turn 65) (or a few select other circumstances)
- great resource:
https://www.medicare.gov/supplement-other-insurance/index.html