What does Medicaid do?

As policymakers debate the future of the national health coverage plan for people with lower incomes, a list of what researchers have learned about its impact

5:00 AM

Author | Kara Gavin

american flag with stethoscope on it
Getty Images

No matter where you live in the United States, or where you get your health insurance, you probably know people who have Medicaid coverage for their health care.

After all, Medicaid covers nearly 80 million people right now. 

Most of them are older adults, people with disabilities, children and pregnant women. 

But many others also rely on it too.

That’s one out of every five people in the U.S., all of them with low incomes.

Medicaid means they can get care from hospitals, doctor’s offices, clinics, nursing homes, pharmacies, home care services and mental health therapists for little or no cost.

Medicaid covers 4 out of every 10 births in the U.S., half of all children, and more than half of long-term nursing home stays.

But all that care costs about $880 billion a year – a sizable chunk of federal and state budgets. 

That’s why policymakers in Washington, D.C., and state capitals are discussing the future of Medicaid and its program for children and teens, the Children’s Health Insurance Program, or CHIP.

To help them make decisions, they can turn to studies done by Medicaid researchers at the University of Michigan Institute for Healthcare Policy and Innovation.

“Over the last 60 years, and especially the last decade, Medicaid has grown into a comprehensive program that not only provides critical health care services to those who need them but also helps support the broader health care system we all rely on, including hospitals, nursing homes and specialized facilities for children’s health,” said John Z. Ayanian, M.D., M.P.P., IHPI’s director and a longtime Medicaid researcher. 

“But with that growth has come growth in costs, and policymakers want to make sure they’re spending wisely. That’s where research comes in.” 

10 things that U-M research has shown about Medicaid

  1. It leads to better health and less risk of dying: 

    A review of all available studies by a pair of U-M researchers comes to this key conclusion for all types of insurance, actually. But they say the effect is especially clear in studies of people enrolled in Medicaid.  

    This review includes the work of another U-M researcher and her colleagues, who studied data from the first three years after states gained access to more federal dollars so they could expand Medicaid to cover more people. 

    They found that deaths dropped by more than 9% among low-income people in expansion states, compared with those in states that didn’t expand Medicaid. 

    If all states had expanded the program, more than 15,000 deaths would have been prevented in just three years. 

  2. It supports the responsible use of health care: 

    Ayanian and his colleagues have studied the people who receive Medicaid coverage through the Healthy Michigan Plan, which in May 2025 includes more than 700,000 people across all counties of the state. 

    Their recent report showed that nearly all surveyed enrollees have a primary care provider (physician, nurse practitioner or physician assistant), that 81% of them saw that provider in the last year, and that long-term enrollees were very likely to get cancer screenings such as mammograms. 

    And those who had regular preventive care were less likely to need emergency care.

  3. It enhances use of high-value care:

    A U-M study compared states that expanded Medicaid in the last decade, with those that didn’t. 

    It showed a 19% increase in the likelihood that a clinic visit by a new Medicaid enrollee would include high value care in expansion states. 

    In non-expansion states that same measure dropped by 24% in the same timeframe. 

    High value care means care that studies have shown a person can really benefit from, because of their specific age, health conditions and other factors.

  4. It helps low income people stay in their jobs, seek jobs or train for jobs if they are able:

    U-M researchers found that half of people in Michigan’s Medicaid expansion program already work full or part-time, even though their income is low enough to qualify for the program. 

    The rest are out of work, studying or training for a career, or unable to work due to health issues, caregiving obligations or other factors.

    U-M researchers found that the percentage of people enrolled in Michigan's Medicaid expansion program who had jobs or were enrolled in school jumped six percentage points in one year, a bigger jump than the state’s overall employment.

    Another U-M study showed that 69% of enrollees who had jobs said they did better at work since enrolling in Medicaid.

    And 55% of those who were out of work said the coverage made them better able to look for a job.

  5. It helps people with mental health conditions, including those with addiction to drugs or alcohol, get care: 
    U-M research finds that about half of the people covered by Michigan’s Medicaid expansion program have what are called behavioral health conditions, including mental health disorders such as depression, or addiction to alcohol or drugs.

    The team found that people with these conditions got an especially big boost in many health and work-related measures after enrolling in the program – bigger than the improvements seen in people who enrolled in the program but didn’t have a behavioral health condition.

    A study by a U-M team also shows that when states “unwound” the special Medicaid enrollment that started during the pandemic, people who were taking medication that treats opioid addiction were more likely to have disruptions in their access to that medicine if they lived in one of the states that had the biggest drops in Medicaid enrollment.

  6. It helps older adults who qualify for both Medicare and Medicaid:

    When someone is over age 65 and has an especially low income even with Social Security benefits and other sources, they can qualify for both Medicare and Medicaid. 

    These “dual eligible” individuals often have a lot of medical needs, and research has shown the positive impact of Medicaid coverage for them.

    For instance, a recent U-M study showed that dual-eligible individuals who lost their Medicaid coverage during the “unwinding” process and then re-enrolled were much more likely to say they missed care due to cost, especially dental care and home care.

    Another U-M study showed that when a dual-eligible person’s income rose to just above Medicaid-eligible levels, they were then much less likely to see the doctor and less likely to be able to afford prescription medications -- especially if they were Black or Hispanic.

  7. Its telehealth coverage helps people get care they wouldn’t get otherwise:

    People with low incomes often face barriers to getting medical care in person, such as transportation challenges and caregiving duties.

    A recent U-M study asked people with Medicaid about their use of video and phone telehealth to get care. 

    Nearly two-thirds of those who had a telehealth appointment in the past year said they received care that they could not or would not have received otherwise.

  8. It helps people improve their financial health:

    Because Medicaid plans are designed for people with low incomes, people with this coverage only have to pay a few dollars, if anything, for appointments or prescriptions. 

    But Medicaid has an even greater impact on the financial health of those who enroll.

    A U-M study showed that in just the first year after enrolling, Michigan Medicaid expansion participants had sizable drops in their unpaid debts — medical debts and overdrawn credit cards in particular — and fewer bankruptcies and evictions, while their credit scores and approvals for car loans rose. 

    Those with chronic illnesses or who had a hospital stay or an emergency department visit after they enrolled saw the largest financial benefits.

  9. It can help people get dental care that can affect their overall health and ability to work:

    While dental coverage under Medicaid varies from state to state, studies suggest it can have a major impact when it’s included.

    Of people who saw a dentist within two years of getting coverage through Michigan’s Medicaid expansion program, 57% said their dental health had improved in that short time, and the majority of those with or without jobs said their improved oral health helped them do a better job at work or made them better able to look for a job.

  10.  It helps keep hospitals and clinics financially stable and able to provide care for all: 

    Ayanian and his colleagues have surveyed health care providers about the impacts of the Medicaid expansion in the state, and looked at data on Michigan hospitals from public sources.

    They found that Michigan hospitals saw the amount of care for which they did not receive payment (also called uncompensated care) drop by half after Medicaid expansion, and that the percentage of hospitalized patients without insurance dropped by 69%. 

    Primary care providers and safety-net clinics also reported improvements in financial stability and their ability to add services. 

Learn more about research on Medicaid by U-M faculty who belong to IHPI. Learn more about IHPI’s evaluation of Michigan’s Medicaid expansion. 

Papers cited:

“The Impact of Health Insurance on Mortality, Annual Review of Public Health,” DOI:10.1146/annurev-publhealth-061022-042335

“Healthy Michigan Plan Evaluation: Section 1115 Demonstration Interim Evaluation Report,” DOI:10.7302/6666

Sign up for Health Lab newsletters today. Get medical tips from top experts and learn about new scientific discoveries every week.

Sign up for the Health Lab Podcast. Add us wherever you listen to your favorite shows.


More Articles About:

Health Care Delivery, Policy and Economics Demographics Wellness & Prevention Primary Care Medicaid
Health Lab word mark overlaying blue cells

Health Lab

Explore thousands of health news & research stories by visiting the Health Lab homepage for more.

Media Contact

University Hospital at U-M Health in the spring with flowering trees in foreground and Survival Flight helicopter visible

Public Relations

Department of Communication at Michigan Medicine

[email protected]

734-764-2220

In This Story

portrait of Ayanian	John

John Zaven Ayanian, MD, MPP

Professor

Stay Informed

Want top health & research news weekly? Sign up for Health Lab’s newsletters today!

Subscribe

Featured News & Stories

Politics depression image
Health Lab

5 ways to manage politically induced stress

A Michigan Medicine psychiatrist offers strategies for how to be mindful of depression and anxiety symptoms around the topic of politics
Minding Memory with a microphone and a shadow of a microphone on a blue background
Minding Memory

Antipsychotic Use in Nursing Homes: Balancing Medication Safety, Policy, and Dementia Care

In this episode, Lauren Gerlach and Matt Davis speak with Theresa Shireman, PhD, Director of the Center for Gerontology and Healthcare Research and a Professor of Health Services, Policy and Practice and Epidemiology at the Brown University School of Public Health. Dr. Shireman’s research focuses on pharmaceutical policy, pharmacoepidemiology, health services research, and medication use among vulnerable populations. Dr. Shireman discusses her recent study, "Impact of Federal Antipsychotic Use Policy in Nursing Homes on New Diagnoses for Approved Indications in Dementia Residents," published in the Journal of the American Geriatrics Society. The study examines whether federal policies designed to reduce antipsychotic use in nursing homes were associated with increases in new diagnoses of conditions, such as schizophrenia, that exclude residents from publicly report antipsychotic quality measures. Using an interrupted time-series design, the researchers examined changes following the 2012 National Partnership to Improve Dementia Care and the 2015 addition of antipsychotic use to the Nursing home Five-Star Quality Rating System. They found that neither policy was associated with an increase in new exclusionary diagnossees, challenging concerns that nursing homes were increasingly assigning these diagnoses to circumvent restrictions on antipsychotic use. The conversation also explores the benefits and risks of antipsychotic medications for people living with dementia, including the potential for serious adverse effects such as sedation, falls, stroke, and increased mortality. Dr. Shireman discusses how public reporting and financial incentives can influence prescribing practices,the limitations of using a single quality measure to evaluate nursing home care, and the importance of balancing medication safety and residents’ individual needs. The discussion highlights the need for shared decision-making among clinicians, nursing home staff, residents, and families, as well as greater investment in staffing, resources, and nonpharmacological approaches to improve quality of life for people living with dementia. The transcript for this episode can be found here.
Well-Being at Michigan Medicine with Dr. Elizabeth Harry
Well-Being at Michigan Medicine

Learning Together: Making Space for Growth at Work

What if well-being starts with how we learn together? On this episode of Well-Being at Michigan Medicine, Elizabeth Harry, M.D., is joined by Rajesh Mangrulkar, M.D., FNAP, Executive Director of U-M’s Center for Interprofessional Practice and Education (IPE), Executive Director of Michigan Medicine RISE (Research. Innovation. Scholarship. Education), and primary care physician of internal medicine whose work focuses on organizational leadership and innovation, and Johnny McGraw, M.A., Marketing & Communications Specialist for both RISE and IPE, about building teams through human connection, psychological safety and learning. They discuss a meeting practice, why leaders shape culture and how investments in collaboration can help health care teams work without asking people to carry everything alone.
A hand holding a prescription bottle with a dollar bill in it
Health Lab

Top 7 tips for choosing Medicare prescription drug coverage for 2027

Prescription drug coverage through Medicare Advantage and Part D plans in traditional Medicare has changed for 2027, and older adults may not know about programs that could help with costs.
Purple shaded illustration of doctor listening to heart of patient on a bed
Health Lab

The AI is listening: Implications of machine generated clinical notes on health care

Michigan Medicine experts argue that use of artificial intelligent scribes during health care visits should be more carefully examined .
Two older women looking at the Medicare website on a laptop screen
Health Lab

Many older adults make Medicare decisions quickly and most don’t change plans, poll finds

Sixty percent of older adults spend less than an hour choosing their Medicare coverage during Open Enrollment, a new poll finds.