Ideally, unexpected medical costs should be covered by a rainy-day fund. Although most financial advisors recommend keeping three to six months of expenses in an emergency fund, few have that kind of money stashed aside. In fact, 66 million U.S. adults have zero dollars saved for an emergency, according to a separate study.

Alternatively, contributions to a flexible spending account or health savings account could cover qualified medical expenses. But less than a third currently contribute to a health savings account that allows them to save money tax-free, the survey said.

Whether that will change under the GOP’s health plan remains to be seen. The Republican health-care bill is President Donald Trump’s first major legislative initiative and aims to fulfill his campaign pledge to repeal and replace Obamacare, the health-care program of his Democratic predecessor Barack Obama.