This fall, as leaves changed, election season heated up, and open enrollment approached, we dove into the latest health policy research.This combined September and October Research Roundup looks at the impact of expiring Marketplace premium tax credits on uncompensated care and health insurance coverage rates, Affordable Care Act (ACA) tax credit cliffs, and how hospital and private equity affiliation affects specialty care prices.
Changes in Health Care Spending and Uncompensated Care under Enhanced Tax Credit Expiration for Marketplace Coverage
Fredric Blavin and Michael Simpson. Urban Institute. September 2025. Available here.
Urban Institute researchers used the Health Insurance Policy Simulation Model (HIPSM) combined with updated Congressional Budget Office (CBO) projections of insurance coverage changes to examine the impact of the expiration of enhanced premium tax credits (EPTCs) on health care spending and uncompensated care.
What it Finds
- If EPTCs expire, 4.8 million more nonelderly adults are projected to become uninsured in 2026, a larger increase than prior estimates. However, not all Marketplace enrollees losing credits would become uninsured: an estimated 3.2 million people would instead shift to employer-sponsored insurance, a 2% overall increase.
- Total health care spending would fall by $32.1 billion in 2026, driven mainly by reduced private insurance and out-of-pocket payments. This includes reductions in spending of $14.2B for hospitals, $5.1B for physician services, $6.9B for “other services”, and $5.8B for prescription drugs.
- At the same time, uncompensated care is projected to rise by $7.7 billion (12%), with hospitals bearing $2.2B of those costs and the remainder spread across physicians, other services, and prescription drugs. Increases would be most pronounced in the 10 states that have failed to expand Medicaid, reflecting wide variation tied to Medicaid expansion status and Marketplace reliance:
- Mississippi (29.1%, $251M), Tennessee (29.2%, $378M), and South Carolina (26.9%, $265M) would see the largest increases.
- Fifteen states, including DC, Hawaii, Minnesota, Connecticut, and Vermont, would see increases of 5% or less, with some under 1%.
Why it Matters
Enhanced premium tax credits have driven record Marketplace enrollment, reduced our national uninsured rate, and supported the financial stability of health care providers. If these subsidies expire, an estimated 4.8 million more people could become uninsured, health system revenue could fall by tens of billions, and uncompensated care could increase by $7.7 billion, placing particular strain on hospitals in rural and non-Medicaid expansion states. Lower coverage rates would likely reduce care utilization and increase unmet health needs, worsening outcomes for individuals. Collectively, these projected changes highlight substantial risks to access, affordability, and provider viability if enhanced PTCs are not extended.
How would eliminating $0 Marketplace premiums affect insurance coverage?
Matthew Fiedler. Brookings. October 2025. Available here.
This Brookings analysis uses publicly available 2025 Marketplace enrollment data, prior research on zero‑premium effects, and scenario modeling to estimate how requiring positive premiums would affect coverage and federal spending.
What it Finds
- Research shows that even a small premium can meaningfully reduce insurance enrollment: When enrollees were asked to shift from a $0 to $1/month plan, a Colorado Marketplace study found 8–16% lower participation and a Massachusetts Marketplace study found that enrollment dropped 12%. Similarly, a Wisconsin Medicaid evaluation found nominal premiums shortened enrollment duration by 13%. These effects occur because the requirement to pay even a minimal premium adds an extra administrative step that causes some people to forgo coverage.
- In 2025, an estimated 34% of Marketplace enrollees (about 8 million people) were in plans with $0 net premiums. A small positive premium has been found to reduce enrollment by on average 12%, which implies that around 960,000 people could lose coverage. This estimate may be conservative, as higher premiums or future policy changes could reduce enrollment further.
- If these enrollees paid the Marketplace average premium of $618.76 (February 2025), federal spending could decrease by approximately $7.1 billion. However, this likely overstates savings because $0‑premium plans are typically lower cost, some enrollees may owe subsidy repayments, and reduced enrollment among healthier individuals could raise overall premiums in the individual market, offsetting federal savings.
- Although some fraudulent broker-driven enrollments exist, evidence suggests they are small relative to overall Marketplace enrollment and the $0 net premium population. Further, claims of widespread “phantom” enrollees are based on flawed evidence.
Why it Matters
Lawmakers are currently debating whether to extend the enhanced premium tax credits for Marketplace enrollees, which are set to expire at the end of this year. If they lapse, enrollees will face, on average, a 114% increase in their net premiums. Some have proposed extending the credits but requiring all enrollees to pay a positive premium, eliminating $0 net premiums for low-income individuals. This approach could lower federal costs but would also reduce coverage among low-income enrollees, underscoring that any potential federal savings come at the cost of access to care.
Eligibility Cliff on ACA Tax Credits Would Make Health Care Unaffordable for Middle-Class Families
Jason Levitis, Claire O’Brien, and Caitlin Rowley Gallamore. Urban Institute. October 2025. Available here.
Urban Institute researchers used policy simulation and scenario modeling with federal poverty guidelines, Marketplace premium data, and enrollment statistics to estimate how reintroducing the ACA premium tax credit (PTC) “cliff” would affect net premiums and affordability for different populations. Originally, eligibility for the ACA’s premium tax credits stopped at 400% of the federal poverty level (or $62,600 in annual income), meaning that everyone above that income threshold was on the other side of a “subsidy cliff” and required to pay the full premium for a Marketplace plan. When Congress enacted the enhanced PTCs in 2021, they capped the level of premium contribution at 8.5% of annual income for households at all income levels, thereby eliminating the subsidy cliff.
What it Finds
- The PTC phases out as individual contributions toward a benchmark plan are capped at a percentage of income. The enhanced PTC allows people above 400% of FPL to receive limited assistance only if premiums are very high.
- For example, a person earning $200,000 with a $20,000 premium would have an expected contribution of $17,000, leaving the PTC to cover just $3,000, or 15% of the total cost.
- Older adults not yet eligible for Medicare and those in high-cost or rural states are disproportionately affected by the PTC cliff, as premiums rise sharply with age and vary widely across states.
- For example, 42% of PTC recipients above 400% of FPL are 55 or older, and 21% of recipients in Wyoming have incomes past the cliff, compared with 14% nationwide.
- The Marketplace is a vital source of coverage for the self-employed and small business owners, especially those with incomes above the cliff. In 2022, the Marketplace covered 18% of all such workers and 28% of enrollees ages 21–64, with enrollment growing to an estimated 5 million in 2025.
- Participation is particularly high in states like Florida, North Carolina, and Wyoming, where at least a quarter of self-employed and small business owners rely on the Marketplace for insurance.
- Tax policy experts note that eligibility cliffs create economic distortions by incentivizing people to reduce work or make suboptimal financial decisions to remain eligible, and undermine fairness by treating similarly situated taxpayers differently. Unlike other tax provisions that phase out gradually, the unenhanced PTC cliff abruptly cuts off benefits, raising questions about fairness by treating similarly situated taxpayers very differently.
Why it Matters
Although the premium tax credits primarily help lower-income individuals, middle-income Americans also face challenges affording health coverage. The PTC cliff is scheduled to return in 2026 unless Congress acts. Nearly all Americans receive federal support for their health coverage—through the employer tax exclusion, Medicare, or Medicaid—and the PTC helps those without other affordable options. Reimposing the cliff would abruptly cut off this assistance for people just above the income threshold, leaving many with projected premiums in the tens of thousands. This change would worsen affordability and financial stability, disproportionately affecting older adults, rural residents, and small business owners.
Hospital- And Private Equity–Affiliated Specialty Physicians Negotiate Higher Prices Than Independent Physicians
Alexander P. Philips, Nandita Radhakrishnan, Christopher M. Whaley, and Yashaswini Singh. Health Affairs. October 2025. Available here.
Researchers at Brown University identified cardiology and gastroenterology specialists by practice ownership (hospital-affiliated, private equity–affiliated, and independent) using multiple datasets, then linked those physicians to 2023 negotiated insurer payment rates from Transparency in Coverage data. The final sample included over 1.36 million negotiated prices and 34,756 specialists across affiliations, focusing on rates from four major national insurers while excluding outliers and inactive “zombie” providers.
What it Finds
- The makeup of physician employment has shifted sharply toward corporate ownership, with over 75 percent of doctors working for hospitals, health systems, or other corporate entities as of 2023. A major driver of this shift has been rapid private equity (PE) acquisition of medical practices, which jumped from 75 deals in 2012 to 484 in 2021. Many of these acquisitions fall below federal reporting thresholds and are therefore largely outside antitrust oversight.
- Consolidation patterns vary widely by state. Hospital-affiliated specialists are most concentrated in Minnesota and Wisconsin (98.0% and 95.4%, respectively), while the highest proportion of specialists in PE-acquired practices are in Arizona and Nevada (16.4% and 10.7%). In general, states with a strong hospital presence tend to have lower PE penetration.
- Hospital-affiliated specialists command the highest negotiated rates, followed by PE-owned practices, while independent physicians have consistently lower prices. Although PE ownership is associated with higher prices, the increase is more modest than what is observed under hospital ownership.
- In 2023, commercial insurers paid more than $18.2 billion for cardiology and gastroenterology procedures delivered by hospital-affiliated specialists and $1.86 billion for those performed by PE-affiliated physicians. If these services had been reimbursed at independent physician rates, spending could have been roughly $2.9 billion (16%) lower for hospital-affiliated procedures and $156 million (8.4%) lower for PE-affiliated procedures.
Why it Matters
Physician practice consolidation is reshaping how Americans access and how much they pay for specialty care. This analysis shows that hospital and private equity ownership of cardiology and gastroenterology practices is associated with significantly higher negotiated prices, contributing to billions in additional spending without clear evidence of improved patient care or better clinician compensation. As consolidation accelerates, policies that strengthen market oversight, improve price transparency, and limit excessive price growth may be needed. Without these measures, consumers could continue to face higher premiums, rising out-of-pocket costs, and fewer affordable care options.
