Only 46% of seniors and baby boomers have a solid understanding of how Medicare works, and half of people over the age of 60 say they have a poor understanding of healthcare reform, a new report finds.

What’s more, 39% of all seniors say their ability to navigate the numerous Medicare options is fair to poor, according to a survey of 1,500 seniors released by UnitedHealthcare and the National Council on Aging.

This lack of knowledge leaves seniors poised to make uninformed choices about their own healthcare, particularly low-income seniors, investigators say. According to the survey, 47% of limited-income seniors have heard of Medicare’s Extra Help program, and only 13% have ever applied for help, through it. Fewer than 31% have heard of the Medicare Savings Program. Depending on the state they live in, seniors who have trouble meeting Medicare premiums and deductibles can apply Medicare Extra Help and the Medicare Savings Program for assistance with coverage.