ALBUQUERQUE, N.M. — More New Mexicans have access to health care than ever before thanks to the expansion of a government program aimed at helping low-income people.

A report from the U.S. Census Bureau shows the number of residents going without health insurance dropped nearly a quarter in 2015. The share of people in the state who were uninsured for the entire year was 10.9 percent, down from 14.5 in 2014.

Republican Gov. Susana Martinez broke ranks with GOP allies in 2013 and moved to expand Medicaid under President Barack Obama’s health care law. Now, nearly 880,000 people — or more than 40 percent of the state’s population — are on the rolls.

More than one in five New Mexicans lacked health insurance coverage when Martinez took office in 2011. That figure now stands at one in nine, state officials said.

“We’ve expanded and reformed Medicaid to make it more patient-centered and provide basic health care for those who need it most,” the governor said.

Despite improvements in insurance coverage, the soaring population of Medicaid patients comes with a price tag. Some state lawmakers are concerned because federal aid for Medicaid is being scaled back, leaving states responsible for picking up more of the tab.

The New Mexico Human Services Department has estimated $60 million to $80 million in new state general fund dollars would be needed for the program for the 2018 fiscal year given price and enrollment increases and reduced federal support.

New Mexico already is facing a budget shortfall for the 2016 and 2017 fiscal years. Martinez and Democratic legislators are no closer to reaching agreement on a special session that would aim to shore up states finances that have been hit hard by the oil and natural gas downturn and weak tax revenues.

Legislative budget analysts also are warning that more cuts will have to be made when the Legislature meets in January to craft the budget for the next fiscal year.

When asked about the ability of the state to pay for the Medicaid expansion while facing a budget deficit, Human Services spokesman Kyler Nerison said: “We’ll continue providing basic health care to New Mexicans who need it most.”