In the first three years of the expanded program, revenue growth for Maryland’s hospitals stayed below the state-set cap of 3.58 percent, saving Medicare $586 million. Spending was lower on hospital outpatient services, including visits to the emergency department that do not lead to hospital admissions. In addition, preventable health conditions and mortality fell.

According to a new report from RTI, a nonprofit research organization, Maryland’s program did not reap savings for the privately insured population (even though inpatient admissions fell for that group). However, the study corroborated the impressive Medicare savings, driven by a drop in hospital admissions. In reaching these findings, the study compared Maryland’s hospitals with analogous ones in other states, which served as stand-ins for what would have happened to Maryland hospitals had global budgeting not been introduced.

But a recent study, published in JAMA Internal Medicine, was decidedly less encouraging.

Led by Eric Roberts, a health economist with the University of Pittsburgh, the study examined how Maryland achieved its Medicare savings, using data from 2009-2015. Like RTI’s report, it also compared Maryland hospitals’ experience with that of comparable hospitals elsewhere.

However, unlike the RTI report, Mr. Roberts’s study did not find consistent evidence that changes in hospital use in Maryland could be attributed to global budgeting. His study also examined primary care use. Here, too, it did not find consistent evidence that Maryland differed from elsewhere. Because of the challenges of matching Maryland hospitals to others outside of the state for comparison, the authors took several statistical approaches in reaching their findings. With some approaches, the changes observed in Maryland were comparable to those in other states, raising uncertainty about their cause.

A separate study by the same authors published in Health Affairs analyzed the earlier global budget program for Maryland’s rural hospitals. They were able to use other Maryland hospitals as controls. Still, after three years, they did not find an impact of the program on hospital use or spending.

Changes brought about by the Affordable Care Act, which also passed in 2010, coincide with Maryland’s hospital payment reforms. The A.C.A. included many provisions aimed at reducing spending, and those changes could have led to hospital use and spending in other states on par with those seen in Maryland.

A limitation of Maryland’s approach is that payments to physicians are not included in its global budgets. “Maryland didn’t put the state’s health system on a budget — it only put hospitals on a budget,” said Ateev Mehrotra, the study’s senior author and an associate professor of health care policy and medicine at Harvard Medical School. “Slowing health care spending and fostering better coordination requires including physicians who make the day-to-day decisions about how care is delivered.”