How much do you know about Medicare? The federal health insurance program for seniors has been around since 1965. Most people are generally aware that it helps to pay for doctor visits, hospital stays, physical therapy, medical equipment supplies and many other healthcare needs. But for the average person, Medicare facts detailing the ins and outs of how the program works may be a mystery.

Whether you're already enrolled in Medicare or expect to be in the near future, you may have questions: How many people are enrolled? Who pays for Medicare? Who can get it? What changes should I know about?

Now's your chance to expand your knowledge. Read on to learn 10 uncommonly known Medicare facts.

1. 2022 Average Monthly Enrollments Are Up from 2021

The average monthly enrollment in Medicare Part A (hospitalization) and/or Part B (outpatient services) is 64.5 million, according to projections from the Centers for Medicare & Medicaid Services (CMS) for the 2022 calendar year. That enrollment figure is up from 63.9 million in 2021.

2. Fewer People Are Enrolled in Medicare Advantage and Other Health Plans Than Original Medicare

Original Medicare has an average enrollment of 35 million per month, while 29.5 million people receive Medicare benefits through Medicare Advantage and other health plans.

3. Some People Younger than 65 Are Eligible for Medicare

While it is primarily a health insurance program for those 65 and older, Medicare may be available earlier for people who have a disability, end-stage renal disease or ALS (also called Lou Gehrig's disease).

4. Funding for Medicare Comes From Two Trust Fund Accounts

Medicare funding comes from two trust fund accounts owned by the U.S. Treasury Department: The Hospital Insurance Trust Fund and the Supplementary Medical Insurance Trust Fund. By law, both of these trust funds must be used exclusively for Medicare. The Hospital Insurance Trust Fund pays for Medicare Part A benefits and administration costs of the program. The Supplemental Medical Insurance Trust Fund pays for Medicare Part B and Part D, along with covering administrative costs.

5. Funding for the Trust Funds Comes From Multiple Sources

The money in the Hospital Insurance Trust Fund comes from payroll taxes, income taxes on Social Security benefits, interest earned on the fund's investments and Medicare Part A premiums from those ineligible for premium-free Part A. The Supplementary Medical Insurance Trust Fund consists of funds authorized by Congress, money from Medicare Part B and Part D premiums and funds from other sources such as the interest earned on the trust fund's investments.

6. National Medicare Spending Increased in 2020

National Medicare spending totaled $829.5 billion in 2020, a 3.5% increase over the previous year, according to the most recent CMS report on National Health Expenditures.

7. Original Medicare Benefit Payments Totaled $379.6 Billion in 2020

This breaks down into $187.4 billion for Part A and $192.2 billion for Part B. Benefits payments in the optional Medicare Part D prescription drug program totaled $104.6 billion.

8. More Than 1,200 U.S. Hospitals Participate in Medicare

However, those 1,200 hospitals are a mere fraction of the program's institutional providers. These providers also include more than 11,000 home health agencies, nearly 15,000 skilled nursing facilities and more than 311,000 medical laboratories.

9. There Are More Than 1.4 Million Non-Institutional Medicare Providers

These providers include physicians, psychiatrists, radiologists, emergency medicine specialists and other healthcare practitioners.

10. Medicare Benefits Have Expanded in Recent Years

Medicare benefits now cover more services. For example, beneficiaries can now get free annual wellness visits and can work with their doctors on a personalized healthcare plan. Medicare also pays for other preventive services like annual mammograms and flu shots, screenings for cervical, prostate and colorectal cancers, and cardiovascular screenings every five years. In addition, Medicare began allowing more telehealth services in response to the Coronavirus pandemic, and some of those options continue to be available.

These Medicare facts can start you on the road to becoming a more informed consumer, armed with the knowledge to better understand the Medicare-related news, policy discussions and healthcare decisions that impact your life.