Medicare and Medicaid are government programs, not private insurance companies

The biggest difference is who runs them. Medicare is a federal program run by the Centers for Medicare & Medicaid Services (CMS). Medicaid is a joint federal and state program, so the rules and coverage vary by state. Private insurance — the kind you buy from companies like Aetna, United Healthcare, or Cigna — is run by for-profit or nonprofit businesses that set their own rules within federal law.

Because Medicare and Medicaid are government programs, they have different goals than private insurers. They aim to cover people who might otherwise have no insurance at all: people over 65, people with disabilities, people with very low income, and pregnant women and children in some states. Private insurers focus on people who can pay premiums, and they make money by collecting more in premiums than they pay out in claims.

This difference in purpose shapes everything else: who can join, what it costs, what gets covered, and how doctors and hospitals get paid.

Key Takeaways

  • Medicare is federal and covers people 65 and older or with certain disabilities, while Medicaid is state-run and covers low-income people, and private insurance is sold by companies to anyone who can afford the premium.
  • Medicare has the same basic rules nationwide, but Medicaid rules change from state to state, and private insurance plans vary widely by company and plan type.
  • Medicare and Medicaid pay doctors and hospitals set rates set by the government, while private insurers negotiate their own rates with providers.
  • Private insurance premiums, deductibles, and copays are usually higher than Medicare or Medicaid costs, but coverage rules are often stricter.
  • You cannot buy Medicare or Medicaid — you must meet specific requirements — but you can buy private insurance anytime if you can afford it.

Who can join each program

Medicare is open to people 65 and older, people under 65 with certain disabilities (including end-stage renal disease and ALS), and people who have received Social Security Disability Insurance for 24 months. You do not choose to join Medicare based on income or employment — age or disability status is what matters.

Medicaid is for people with low income. The income limit varies by state and by family size. Some states cover adults with income up to 138% of the federal poverty line; others have lower limits. Medicaid also covers pregnant women, children, people over 65 with low income, and people with disabilities in all states, though the income thresholds differ.

Private insurance is available to anyone who can pay the premium, regardless of age, income, or health status. However, employers often offer group plans to their employees, and some people buy individual plans on the open market or through the health insurance marketplace.

How costs work: premiums, deductibles, and copays

Medicare has a monthly premium for Part B (doctor and outpatient care) and Part D (prescription drugs). In 2024, the standard Part B premium is $164.90 per month, though it varies based on income. There is also a deductible — the amount you pay before Medicare starts to pay — and copays or coinsurance for each visit or service. Medicare Part A (hospital care) has no monthly premium for most people, but there is a deductible if you are admitted to the hospital.

Medicaid has no monthly premium in most states. You pay little or nothing out of pocket for covered services, though some states charge small copays for doctor visits or prescriptions. The exact copay rules vary by state.

Private insurance premiums vary widely depending on the plan, the insurer, and your age and health. A family plan might cost $400 to $1,500 or more per month. Deductibles can range from $500 to $5,000 or higher per year. Copays for a doctor visit might be $20 to $50, and coinsurance (your share of the cost after the deductible) can be 20% to 40% of the bill.

What services are covered

Medicare covers hospital stays, doctor visits, lab tests, imaging, preventive care, and prescription drugs (under Part D). It does not cover dental, vision, hearing aids, or long-term care in a nursing home. Some people buy supplemental insurance (called Medigap) to fill these gaps.

Medicaid covers doctor visits, hospital stays, lab tests, preventive care, and prescription drugs in all states. Many states also cover dental, vision, and hearing aids. Medicaid often covers more long-term care services than Medicare, including nursing home care and in-home care for people who may have access to.

Private insurance plans vary. Some cover dental and vision; others do not. Coverage for mental health, physical therapy, and other services depends on the specific plan. You have to read the plan documents to know what is covered.

How doctors and hospitals are paid

Medicare pays doctors and hospitals a set fee for each service, set by the federal government. A doctor visit might be reimbursed at $100; an X-ray at $50. These rates are the same nationwide (with small adjustments for geography). Doctors and hospitals cannot charge you more than Medicare allows, though they can choose not to accept Medicare patients.

Medicaid also pays set rates, but the rates are lower than Medicare and vary by state. A doctor visit might be reimbursed at $40 to $60 depending on the state. Because Medicaid pays less, some doctors and hospitals limit the number of Medicaid patients they see or do not accept Medicaid at all.

Private insurers negotiate rates with each hospital and doctor group. One insurer might pay $120 for a doctor visit; another might pay $90. These rates are confidential and vary by region and by provider. This is why your out-of-pocket cost can differ dramatically depending on which private insurance plan you have.

How to enroll and when coverage starts

You enroll in Medicare automatically if you are receiving Social Security benefits at 65. If you are not receiving Social Security, you must enroll through Social Security Administration or Medicare.gov. Coverage starts the first day of the month you turn 65 or the month you become may be able to access due to disability.

You enroll in Medicaid through your state's Medicaid office or through the health insurance marketplace. The process and timing vary by state. In most states, coverage starts the first day of the month after you are found to meet the income and other requirements.

You can enroll in private insurance through your employer, the health insurance marketplace, or directly from an insurance company. Coverage usually starts on the first day of the month after you enroll, though some employer plans have different start dates.

What happens if you do not have insurance

If you are 65 or older and do not enroll in Medicare, you may face a permanent penalty on your Part B and Part D premiums. The penalty is 10% of the standard premium for each year you were may be able to access but did not enroll. This penalty stays with you for life.

If you are may be able to access for Medicaid and do not enroll, you straightforward do not have coverage. There is no penalty, but you are responsible for the full cost of any medical care you receive.

If you do not have private insurance and do not may have access to for Medicare or Medicaid, you can still receive emergency care at a hospital, but you will receive a bill. Some hospitals have financial information programs for uninsured people with low income.

Frequently Asked Questions

Can I have Medicare and Medicaid at the same time?

Yes. If you are 65 or older with low income, you may may have access to for both. People with both are called "dual may be able to access." Medicaid covers costs that Medicare does not, like long-term care and some dental services. Your state's Medicaid office can tell you if you may have access to.

Can I use my Medicare card at any doctor or hospital?

Most doctors and hospitals accept Medicare, but not all. Before you schedule an appointment, call and ask if the provider accepts Medicare. Some providers accept Medicare for some services but not others. Your Medicare card lists a customer service number you can call to find in-network providers.

What is the difference between Medicare Advantage and Original Medicare?

Original Medicare is the federal program run directly by CMS. Medicare Advantage is a private insurance plan that is paid by Medicare to cover your benefits. Both are part of Medicare, but Medicare Advantage plans have different rules, copays, and networks. You choose which one to use when you enroll.

If I lose my job, can I keep my private insurance?

You may be able to continue your employer's health plan for up to 18 months through a law called COBRA, but you pay the full premium yourself (usually $400 to $1,500 per month). You can also buy an individual plan through the health insurance marketplace. If you are 65 or older, you can enroll in Medicare instead.

Do I have to pay taxes on Medicare or Medicaid benefits?

No. Medicare and Medicaid benefits are not taxable income. However, if you have other income, some of your Social Security benefits may be taxable. A tax professional can help you understand your specific situation.