The Current Numbers

As of 2023, roughly 66 million people were enrolled in Medicare and about 72 million in Medicaid, though these numbers shift month to month as people turn 65, lose or gain income, and move between states. Medicare covers nearly all Americans 65 and older, plus some younger people with disabilities or end-stage renal disease. Medicaid covers low-income adults, children, pregnant people, and seniors in every state, but the income limits and who qualifies vary significantly by state.

These are not separate groups — some people hold both Medicare and Medicaid at the same time. These individuals, called "dual may be able to access," typically are seniors with limited income. Understanding these overlapping populations matters because the rules, costs, and coverage differ depending on which program or programs you are in.

Key Takeaways

  • Medicare enrollment is around 66 million people, mostly those 65 and older, while Medicaid covers approximately 72 million people across all ages and income levels.
  • About 12 million people hold both Medicare and Medicaid simultaneously, usually because they are seniors with low income.
  • Medicaid enrollment varies by state because each state sets its own income thresholds and decides which groups to cover beyond the federal minimum.
  • Both programs have grown over the past decade, with Medicaid expansion under the Affordable Care Act increasing coverage in participating states.
  • The actual number of people in each program changes monthly as people age into Medicare, change jobs, move states, or experience income changes.

Why Medicare and Medicaid Numbers Matter

Knowing how many people use each program tells you something important: these are not niche services. Medicare and Medicaid together cover roughly one in four Americans. That scale affects everything from wait times at doctors' offices to the types of providers available in your area and the research funding that goes into treatments for conditions common in older or lower-income populations.

The numbers also show you that both programs are stable, long-running parts of the health system. They are not experimental or temporary. If you are approaching 65 or think you might be low-income enough for Medicaid, you are entering a system that has covered millions of people for decades.

Who Is Counted in Medicare

Medicare's 66 million enrollees break down into several groups. The vast majority — about 60 million — are people 65 and older. The remaining roughly 6 million are younger people with disabilities who have been receiving Social Security Disability Insurance (SSDI) for at least two years, or people of any age with end-stage renal disease or ALS (amyotrophic lateral sclerosis).

Medicare enrollment grows by roughly 10,000 people per day as the population ages. This steady growth is one reason Medicare's finances are watched closely by policymakers — the ratio of working-age people paying into the system to retirees drawing from it continues to shift.

Who Is Counted in Medicaid

Medicaid's roughly 72 million enrollees span all ages and include children, working-age adults, pregnant people, parents, seniors, and people with disabilities. Unlike Medicare, which is a federal program with the same rules nationwide, Medicaid is jointly run by the federal government and each state. This means a person who qualifies in one state might not in another, and the services covered can differ.

Medicaid enrollment surged during the COVID-19 pandemic and has remained higher than pre-pandemic levels. Many states expanded Medicaid to cover more low-income adults under the Affordable Care Act, which increased enrollment in those states. Other states have not expanded, so their Medicaid programs cover fewer working-age adults. This is why the number of Medicaid enrollees varies so much by geography.

The Overlap: People With Both Medicare and Medicaid

Approximately 12 million people hold both Medicare and Medicaid. These "dual may be able to access" individuals are usually seniors 65 and older whose income and assets fall below their state's Medicaid limit. Because Medicare does not cover long-term care, dental, vision, or hearing, Medicaid fills those gaps for people who cannot afford to pay out of pocket.

Being dual may be able to access changes how your coverage works. Medicare is your primary payer for most medical services, and Medicaid covers what Medicare does not. Your out-of-pocket costs are typically lower than for someone on Medicare alone, but you may have to navigate two separate systems and two sets of rules. Some states offer special programs designed specifically for dual may be able to access people to simplify this coordination.

How Enrollment Numbers Have Changed

Medicare enrollment has grown steadily as the population ages. In 2010, about 47 million people were on Medicare; by 2023, that number had climbed to 66 million. This growth is expected to continue as more Baby Boomers turn 65.

Medicaid enrollment has been more volatile. It grew significantly after the Affordable Care Act became law in 2010, especially in states that chose to expand the program. During the COVID-19 pandemic, enrollment jumped because the federal government temporarily prevented states from removing people from the rolls. When that protection ended in 2023, many states began the process of reviewing and removing people who no longer met the income or other requirements, which caused enrollment to drop. The current numbers reflect this post-pandemic adjustment period.

What These Numbers Tell You About Access

With nearly one in four Americans on Medicare or Medicaid, these programs shape the entire health care landscape. Most doctors accept at least one of these programs, though some accept neither. Hospitals, nursing homes, and home health agencies all structure their operations around serving large numbers of Medicare and Medicaid patients.

The size of these programs also means there is substantial public information available. You can find detailed guides about coverage, costs, and how to navigate each program. You are not entering an obscure system — you are entering one that millions of people use and that generates extensive documentation and support resources.

Frequently Asked Questions

Can I be on both Medicare and Medicaid at the same time?

Yes. If you are 65 or older and your income and assets are low enough, you can hold both. Medicaid becomes your secondary payer and covers costs Medicare does not, like long-term care and dental. About 12 million people are in this situation.

Why do Medicaid numbers change so much between states?

Each state sets its own income limits and decides which groups to cover beyond the federal minimum. States that expanded Medicaid under the Affordable Care Act cover more people than states that did not. This is why a person might may have access to in one state but not in another.

Are these numbers the same every month?

No. Medicare and Medicaid enrollment changes constantly as people turn 65, move, change income, or experience life changes. The figures cited here are snapshots from a specific time and will shift over the coming months and years.

Does being on Medicare or Medicaid mean I have to use a specific doctor?

Not necessarily. Original Medicare lets you see any doctor who accepts Medicare. Medicaid rules vary by state and plan type. Some Medicaid plans require you to choose a primary care doctor, while others do not. Check your specific plan's rules.

What happens to Medicaid enrollment if I get a job and earn more money?

If your income rises above your state's Medicaid limit, you will lose Medicaid coverage. However, you may be able to purchase a plan through the health insurance marketplace, and you might may have access to for a tax credit to help pay the premium depending on your income level.