Medicaid is the largest health insurance program in the United States, covering over 75 million people as of early 2026. It functions as the financial backbone of healthcare for low-income Americans, and its reach extends far beyond individual coverage. Medicaid shapes hospital survival in rural communities, drives down mortality rates in states that have expanded it, and finances nearly half of all births in the country.
Who Medicaid Covers
Nearly half of all Medicaid and CHIP enrollees, about 47.6%, are children. The rest includes low-income adults, pregnant women, seniors in nursing homes, and people with disabilities. This mix matters because Medicaid isn’t just one thing: it’s simultaneously a children’s health program, a long-term care safety net for elderly Americans, and the primary source of addiction and mental health treatment for millions of adults.
No other insurance program in the U.S. serves this many roles at once. Private insurance doesn’t cover long-term nursing home stays. Medicare doesn’t cover most working-age adults. Medicaid fills gaps that would otherwise leave tens of millions of people with no realistic path to medical care.
The Effect on Death Rates
States that expanded Medicaid eligibility under the Affordable Care Act saw a measurable drop in deaths. A national study published in The Lancet Public Health found that expansion was associated with a reduction of roughly 12 deaths per 100,000 adults. Scaled across an entire state population, that translates to hundreds or thousands of lives per year depending on the state’s size.
The mechanism is straightforward: people who gain insurance coverage are more likely to get screened for cancer, manage chronic conditions before they become emergencies, and fill prescriptions they previously skipped. Mortality reductions showed up most clearly among adults in the income range that expansion was designed to reach, those earning too much to qualify for traditional Medicaid but too little to afford private plans.
Managing Chronic Disease
Diabetes and high blood pressure are two of the most common conditions among low-income adults, and both require consistent monitoring and medication to prevent serious complications like stroke, kidney failure, or heart attack. Community health centers in Medicaid expansion states saw greater improvement in the percentage of patients with controlled diabetes and blood pressure compared to centers in states that didn’t expand.
Expansion states also saw a 7% increase in hypertension diagnosis rates, while non-expansion states saw a 6% decline. That gap likely reflects the difference between catching a problem early and never knowing about it until a medical emergency. Screening for blood sugar control increased in both types of states, but the rise was larger in expansion states. Black and Hispanic patients in expansion states saw especially notable improvements in disease management, narrowing disparities that have persisted for decades.
Substance Use and Mental Health Treatment
Medicaid is the single largest payer for addiction treatment in the country. Among enrollees diagnosed with a substance use disorder, about 74% received treatment or supportive services in 2020. For opioid use disorder specifically, 63% of diagnosed enrollees received medication-based treatment, which is the most effective approach for preventing relapse and overdose death.
These numbers aren’t perfect. Only about 1 in 10 enrollees with alcohol use disorder received medication treatment, despite clinical guidelines recommending it. Racial gaps persist: roughly 7 in 10 White enrollees with opioid use disorder received medication, compared to just 4 in 10 Black enrollees. And only 12% of youth with opioid use disorder got medication treatment. Still, without Medicaid, the majority of people in these groups would have no coverage for addiction care at all, particularly in states hit hardest by the opioid crisis.
Pregnancy and Newborn Health
Medicaid finances about 41% of all births in the United States, making it the single largest payer of pregnancy-related services. In some Southern and rural states, that figure is considerably higher. This coverage pays for prenatal visits, labor and delivery, and postpartum care for mothers who would otherwise go without.
Prenatal care is one of the most cost-effective interventions in medicine. Regular checkups during pregnancy catch complications like preeclampsia, gestational diabetes, and preterm labor risk early enough to intervene. For the roughly 1.5 million babies born each year under Medicaid coverage, the program’s role begins before birth and often extends through childhood.
Protection Against Medical Debt
Medical bills are the leading cause of debt collections in the United States, and Medicaid expansion has proven to be one of the most effective tools for reducing that burden. Research from the Center for Retirement Research at Boston College found that expanding Medicaid in areas with high concentrations of low-income residents reduced the number of unpaid bills going to collection agencies and cut individual collection balances by about $1,000.
The effect isn’t limited to medical bills alone. When people aren’t facing catastrophic healthcare costs, they’re also less likely to fall behind on rent, utilities, and other obligations. Minnesota, which operates one of the most generous Medicaid programs in the country, has the lowest rate of medical debt collection of any state, at just 3% of residents. That’s not a coincidence. Comprehensive coverage prevents the financial spiral that starts with an unexpected emergency room bill and ends with damaged credit, eviction, or bankruptcy.
Keeping Rural Hospitals Open
Rural hospitals operate on razor-thin margins, and a large share of their patients are either uninsured or on Medicaid. When states declined to expand Medicaid, those hospitals lost out on reimbursement for patients who would have been covered under expansion. One-third of rural hospital closures over the past decade are directly attributable to states declining Medicaid expansion.
When a rural hospital closes, the consequences cascade. Remaining nearby hospitals absorb more uncompensated care, stretching their own budgets thinner. Residents face longer drives for emergency care, which can be the difference between surviving a heart attack or stroke and not. Local economies lose one of their largest employers. Medicaid, in this context, isn’t just health insurance for individuals. It’s infrastructure funding that determines whether a community has a hospital at all.
The Cost Question
Critics of Medicaid often point to its cost, and the program is genuinely expensive. But the financial structure of expansion tells a more nuanced story. When Medicaid expansion began in 2014, the federal government covered 100% of costs for newly eligible adults. That share gradually decreased, and since 2020, states have paid 10% of expansion costs while the federal government covers 90%. That’s still a significantly better deal than traditional Medicaid, where states typically pay 30% to 50% of costs.
A study in Health Services Research found that while expansion was associated with a 21% increase in total per capita Medicaid spending, it led to a 25% increase in federal funding flowing into states. Critically, expansion was not associated with a significant increase in state general fund spending. In other words, states got substantially more healthcare coverage without meaningfully increasing what they paid out of their own budgets. The federal dollars also ripple through local economies: hospitals get paid, healthcare workers earn salaries, and the financial strain of uncompensated emergency care decreases.
Access Gaps That Remain
Medicaid’s importance doesn’t mean the program is without problems. Only 74% of physicians accept new Medicaid patients, compared to 88% for Medicare and 96% for private insurance. Lower reimbursement rates are the primary reason. In practice, this means Medicaid enrollees sometimes face longer wait times for appointments, fewer specialists willing to see them, and a narrower choice of providers.
Ten states still haven’t expanded Medicaid, leaving an estimated coverage gap where adults earn too much for traditional Medicaid but too little for marketplace subsidies. In those states, the uninsured rate remains higher, hospital finances are more precarious, and the mortality and chronic disease benefits seen in expansion states simply haven’t materialized. The importance of Medicaid is perhaps most visible in the places where it’s absent.