The expansion of Medicaid has saved more than 27,000 lives since 2010, according to the most definitive study yet on the program’s health effects.

Poor adults who gained Medicaid coverage after the Affordable Care Act expanded access were 21 percent less likely to die during a given year than those not enrolled, the research shows. By analyzing federal records on 37 million Americans, two economists found that deaths fell not only among older enrollees but also among those in their 20s and 30s — a group often assumed to have few medical needs, and who would have been far less likely to qualify for Medicaid before the expansion.

The findings were published this month in a National Bureau of Economic Research working paper, as House Republicans were drafting a plan that could significantly cut Medicaid, which covers 71 million low-income or disabled Americans. The House Energy and Commerce Committee, which oversees the program, approved a suite of policies on Wednesday that the Congressional Budget Office estimated would cause millions of people to lose their coverage in the years ahead.

The study’s authors said that the publication timing was coincidental — their research has been in progress for two years — but acknowledged that the findings were especially relevant to the current budget discussions.

The researchers found that, on average, it costs Medicaid $179,000 to save a year of life — similar to the amounts spent on health care interventions like cervical cancer screenings and leukemia treatment. It is less than the combined public and private spending on interventions like safety inspections for cars or the removal of asbestos from buildings.