Medicare and Medicaid are government programs, not commercial insurance you buy from a company

Medicare and Medicaid are both run by the federal government, but they work differently from private insurance sold by companies like Aetna or Blue Cross. With private insurance, you pay a monthly premium to a company, and that company decides what doctors and hospitals it will cover. With Medicare and Medicaid, the government itself is the payer — you don't buy a policy from a middleman. The government sets the rules about who can join, what services are covered, and how much doctors get paid.

This matters because it changes how claims work, what your costs are, and which doctors will see you. A private insurer can drop you or raise your premium if you get sick. Medicare and Medicaid cannot. But they also have stricter limits on which providers participate and how much they reimburse.

Key Takeaways

  • Medicare is federal health insurance for people 65 and older, regardless of income, while Medicaid is a joint federal-state program for people with low income at any age.
  • Medicare has the same rules nationwide; Medicaid rules vary significantly by state, including who qualifies and what services are covered.
  • Private insurance is sold by companies and can deny coverage or raise premiums based on health; Medicare and Medicaid cannot.
  • Medicare requires you to enroll during specific windows or pay a penalty; Medicaid enrollment is open year-round in most states.
  • All three programs have different cost structures — Medicare uses premiums and deductibles, Medicaid often has minimal costs, and private insurance varies widely.

Who qualifies: age and income matter differently for each

Medicare is based on age and work history, not income. You become may be able to access at 65 if you or your spouse paid Medicare taxes while working. You can join earlier if you have been receiving Social Security disability benefits for 24 months, or if you have end-stage renal disease or ALS. Income does not matter — a millionaire and someone living in poverty both may have access to at 65.

Medicaid is based on income and family size. Each state sets its own income limits, so a person who qualifies in one state may not may have access to in another. Some states expanded Medicaid to cover adults earning up to 138% of the federal poverty level; others have much stricter limits. Medicaid also covers children, pregnant people, and people with disabilities at income levels that vary by state.

Private insurance does not have income or age requirements, but insurers can refuse to cover you or charge more based on your health history. They can also set their own rules about pre-existing conditions, though the Affordable Care Act limits how much they can do this.

How costs work: premiums, deductibles, and out-of-pocket limits

Medicare has three parts with different costs. Part A (hospital insurance) is free for most people who paid Medicare taxes. Part B (doctor visits and outpatient care) costs a monthly premium that changes each year — it was $164.90 per month in 2024, but varies based on income. Part D (prescription drugs) also has a monthly premium that varies by plan. You pay a deductible before Medicare starts paying, and you pay a percentage of costs after that.

Medicaid costs vary by state. Many states charge little or nothing for Medicaid coverage — no premiums, no deductibles, or very small copays per visit. Some states charge small premiums for people above a certain income level. Out-of-pocket costs are usually much lower than private insurance.

Private insurance premiums, deductibles, and out-of-pocket limits vary widely depending on the plan. A cheap plan might have a $3,000 deductible and high copays; an expensive plan might have a $500 deductible and lower copays. The insurer sets all these numbers, and they can change them each year.

Rules are the same everywhere with Medicare; Medicaid rules change by state

Medicare is uniform nationwide. If you have Medicare Part B in California, you have the same coverage as someone with Medicare Part B in Texas. The deductible is the same, the copays are the same, and the list of covered services is the same. This makes it predictable — you know what to expect no matter where you live or move.

Medicaid is a partnership between the federal government and each state. The federal government sets a floor — states must cover certain services and certain groups of people — but states can cover more. One state might cover dental care; another might not. One state might cover therapy; another might limit it. If you move from one state to another, your Medicaid coverage may change, and you may need to reapply.

Private insurance rules are set by each company. Two plans from the same company can have different rules. A plan sold in one state may not be sold in another. This makes private insurance harder to compare and predict.

Enrollment windows: when you can sign up

Medicare has strict enrollment periods. You can sign up during the seven-month window that starts three months before you turn 65. If you miss this window, you pay a permanent penalty on your premiums for as long as you have Medicare. There is also an annual open enrollment period from October 15 to December 7 when you can change plans, but you cannot join Medicare for the first time during this period.

Medicaid enrollment is open year-round in most states. You can apply any time, and coverage usually starts the first day of the month after you apply. Some states have continuous enrollment; others pause it during certain periods. You should check your state's rules, but generally you do not have to wait for a specific enrollment window.

Private insurance has open enrollment periods set by the employer or the marketplace. If you buy it yourself through the Affordable Care Act marketplace, open enrollment is November 1 to January 15. If you miss it, you can only enroll if you have a may have access to life event like losing a job or having a baby.

How providers are paid and what that means for you

Medicare pays doctors and hospitals a set amount for each service. The government decides the price. Doctors can choose to accept Medicare or not, but if they do, they must accept the Medicare price — they cannot charge you more. This is called "accepting assignment." Most doctors accept Medicare because the volume is large and predictable.

Medicaid also pays providers a set amount, but the amount is often lower than Medicare. Some doctors accept Medicaid; others do not, because the reimbursement is too low. This can make it harder to find a Medicaid provider in some areas, especially for specialists.

Private insurance negotiates prices with doctors and hospitals. The insurer and provider agree on a price, which is usually higher than Medicare or Medicaid pays. If you go to an out-of-network provider, you may pay much more. Private insurers can also change which providers are in-network from year to year.

What happens if you lose coverage

You cannot lose Medicare because you get sick or your income changes. Once you are enrolled, you stay enrolled. You pay your premiums and you keep your coverage. The only way to lose Medicare is to lose your citizenship or move out of the country.

Medicaid can end if your income rises above your state's limit, if you no longer meet other may be able to access rules, or if you do not recertify when your coverage period ends. Each state has different rules about how often you must recertify. During the COVID-19 pandemic, states were not allowed to end Medicaid coverage, but that pause ended in 2023. Now states can end coverage if you do not recertify or if you no longer may have access to.

Private insurance can end if you stop paying the premium, if the company stops offering the plan, or if the company leaves your state. If you lose private insurance, you have 60 days to find new coverage or you may face a gap in protection.

Frequently Asked Questions

Can I have both Medicare and Medicaid at the same time?

Yes. People who are 65 or older and have low income can have both. This is called "dual may be able to access." Medicaid covers costs that Medicare does not, like long-term care and dental care in some states. If you are dual may be able to access, Medicaid is your secondary payer.

If I have private insurance through my job, do I still need to sign up for Medicare at 65?

Yes, unless your employer has 20 or more employees. If your employer is large, you can delay Medicare without penalty. If your employer is small, you should sign up for Medicare at 65 or pay a penalty later. Talk to your employer's benefits person to find out the size threshold.

Why is it harder to find a doctor who takes Medicaid than Medicare?

Medicaid pays doctors less than Medicare or private insurance. In some states, Medicaid reimbursement is so low that doctors cannot afford to see Medicaid patients. Rural areas and specialists are especially affected. This is a real access problem in some states, though it varies.

Can a private insurance company refuse to cover me because I have a pre-existing condition?

No, not since the Affordable Care Act passed in 2010. Private insurers cannot deny you coverage or charge you more because of a pre-existing condition. They can still charge more based on age or tobacco use, but not health history.

What if I am under 65 and do not may have access to for Medicaid — what are my options?

You can buy private insurance through your employer, through the Affordable Care Act marketplace, or directly from an insurer. If your income is low but above your state's Medicaid limit, you may may have access to for a tax credit that lowers your marketplace premium. You can also look into short-term health plans, though these have limited coverage.