Dow is a celebrated scholar of the economic aspects of health insurance and was interim dean of the School of Public Health from 2018–2019. He is a recipient of the Kenneth J. Arrow Award given by the International Health Economics Association and received his PhD in economics from Yale.

We interviewed William Dow , professor of health policy and management at UC Berkeley School of Public Health and director of the Center on the Economics and Demography of Aging , about what these cuts to Medicaid mean to Americans.

According to the US Department of Health and Human Services, Medicaid is a “joint federal and state program that helps cover medical costs for some people with limited income and resources. The federal government has general rules that all state Medicaid programs must follow, but each state runs its own program.”

President Donald Trump signed the One Big Beautiful Bill Act (OBBB) into law on July 4, 2025. Among other provisions, the bill raises the debt ceiling by $5 trillion annually and also makes a 15% cut to Medicaid spending, according to KFF.

Why is Medicaid so important to the health of the U.S. population?

Medicaid provides health insurance to low-income populations in the U.S. Because private health insurance premiums have become so expensive, many people on Medicaid would be uninsured if not covered by Medicaid, while others could pay for private insurance only by cutting back on other necessities that indirectly affect health. Extensive research has shown that cutting Medicaid coverage leads to worse health and increased risk of premature mortality.

The new bill—formally named the One Big Beautiful Bill Act (OBBB)—which Trump signed into law on July 4, 2025, includes cuts to Medicaid of almost $1 trillion over the next 10 years. The Congressional Budget Office estimates that this means that 11.8 million Americans may lose their health insurance. Do you think that figure is accurate and why?

It’s the best estimate that I have seen. The Congressional Budget Office has a strong reputation for high quality, non-partisan analysis, and I have great respect for the analysts who work there. Having said that, this type of estimate requires many assumptions, so I would not be surprised if the actual OBBB effect was 25 percent larger or smaller. For example, this estimate requires assumptions about how much states may raise their own spending to backfill lost federal funds, which could shrink the uninsurance increase. But regardless of the precise effect, it is undoubtedly the largest, most regressive cut to federal health benefits that has ever been enacted in the U.S.

Are there changes going on with the Affordable Care Act (ACA, also sometimes referred to as Obamacare) that will also affect the number of Americans who have health insurance?

Unfortunately, yes. To fund larger tax cuts, the bill avoided extending current subsidies that help make ACA marketplace insurance plans affordable. Those subsidies will expire at the end of 2025, leading to premiums that double for many people, which the Congressional Budget Office estimates will cause more than 4 million more people to become uninsured. Along with the Medicaid cuts, and other provisions making it harder for people to enroll in ACA plans even when eligible, the Congressional Budget Office estimates that the total number of uninsured will rise by 17 million people by 2034.

How will the number of people without insurance affect the healthcare system across the US?

These cuts will indirectly harm the rest of the population by raising financial pressure on health facilities. More uninsured people implies more unpaid medical bills, which leads to health care price increases for everyone else. Ultimately, health care facilities in low-income areas will have to cut back on services, and based on past experience we can confidently predict that some safety net clinics and hospitals will be forced to close.

Which populations are most at risk to lose insurance?

The biggest adverse impacts will be on those who most gained insurance from the ACA, which was low-income adults ages 18–64 without young children. That is the group that will have new work requirements to spend at least 80 hours per month in verified work-related activities. States that have previously passed such work requirements have seen many people lose insurance, though often because the bureaucracy made it too difficult to prove that they were actually complying and so should have been Medicaid eligible. Another population at high risk is immigrants, for example, most on humanitarian visas will now be barred from Medicaid.

Furthermore, many are concerned that increased state budgetary pressure from other OBBB provisions could cause states such as California to decide to rescind state-funded health care assistance for undocumented immigrants [undocumented immigrants are not provided with standard Medicaid benefits through federal funding]. Some adults over age 65 are also predicted to lose dual Medicaid coverage that helps them pay for Medicare cost-sharing, though fortunately the overall effects on older adults and children will be more muted compared to other groups.

How will these cuts affect California?

I have seen a range of estimates on the predicted number of Californians that will lose insurance. After the ACA was implemented in 2013, the uninsurance rate in California dropped from 17 percent down to our current 6 percent, but analysts now project that it could rise back to well over 10 percent. That is in addition to the adverse health effects of the predicted millions of Californians who will lose their SNAP food assistance benefits (formerly called Food Stamps) due to other provisions of the OBBB Act.

What about rural areas?

Because of higher poverty, Medicaid coverage rates are generally higher in rural areas, so the OBBB cuts are predicted to disproportionately harm rural areas. Last-minute politicking by Republican Senators with large rural populations resulted in a new rural fund intended to offset impacts on rural health care providers, but the fund is far too small relative to the predicted adverse effects, so prominent rural health care experts are predicting some closures of rural hospitals and clinics as a result.

Are there other provisions in this new law that specifically affect health coverage and nursing home care for older adults?

Although the primary focus was not on older adult health care, various provisions will have adverse effects. One is that the loss of dual Medicaid coverage for some Medicare enrollees will make it harder for them to financially access long-term care.

Another effect that nursing home experts are concerned about is a provision that bars enforcement of a Biden-era rule mandating minimum staffing levels in long-term care facilities, so the result is that the BBBA is preventing nursing home quality improvements.

More indirectly, state budgetary pressure has often led to cuts in state-funded home and community-based services for older adult caregiving, so that is a potential concern. The biggest wildcard is that the magnitude of the tax cuts in the bill will raise the national debt by about three trillion dollars over the next decade, which would trigger a deficit-reduction provision that would significantly cut Medicare provider reimbursement rates—unless Congress chooses to waive their own rules.

Are there any other thoughts you have?

Not all of these adverse effects are inevitable. Many of the biggest insurance cuts will not take effect for another several years, so there is time for policy reversals under a future Congress and administration. States can also choose to respond in various ways: The unprecedented Medicaid cut was accompanied by even bigger federal tax cuts for the wealthy and for corporations, and states could implement corresponding state-level tax increases in order to partially backfill federal safety net cuts. States will also be responsible for implementing processes such as verifying the Medicaid work requirement —and the smoother they make the bureaucracy, the more people will be able to retain the benefits for which they are still eligible. So health policy engagement is more important than ever!