Millions of people in the U.S. may be missing out on funds available under Obamacare to help them afford health insurance, the federal government said, as the fourth sign-up season for the program approaches.

About 2.5 million people with individual or family insurance plans outside of Obamacare could be eligible for tax subsidies if they bought through the program, the U.S. Department of Health & Human Services said in a report Tuesday. In addition, about 9 million people who are uninsured may be eligible for subsidies to help them buy plans, according to the report.

“Today’s data show millions more Americans could benefit,” HHS Secretary Sylvia Burwell said in a statement accompanying the report. Inside the Patient Protection and Affordable Care Act, as the 2010 law is formally known, there are about 9 million people getting subsidies.

The U.S. is pushing to get more people covered by the ACA, in part by emphasizing how subsidies can help make insurance more affordable despite rising premiums. The cost of individual plans for next year sold through the law’s markets will climb by about 25 percent on average, according to ACASignups.net, a site that tracks the law.

Subsidies are available to individuals and families who make as much as four times the poverty level, or about $100,000 for a family of four. As income rises, the subsidies decrease.

The analysis also shows how many individuals may feel the full effect of this year’s rate increases. About 6 million people are buying health plans in the individual market, either on- or off-exchange, and aren’t eligible for subsidies.

About 29 million people, or 9.1 percent of the population, lacked health insurance in 2015, according to the U.S. Census Bureau.

This article was provided by Bloomberg News.