WASHINGTON — Sen. Kamala Harris introduced legislation Thursday that would require health insurance companies to cover the HIV prevention drug PrEP, a first-of-its-kind bill that the California Democrat timed to coincide with Pride Month.

The bill would require that insurance plans cover the full cost of PrEP, or pre-exposure prophylaxis, as well as require initial tests and related follow-up visits with a doctor.

That would go beyond a recommendation this month by the U.S. Preventive Services Task Force, a panel of government-appointed prevention experts, that PrEP be given to people at high risk of contracting HIV.

The medicine, sold under the brand name Truvada, can reduce the risk of contracting HIV by up to 99% if taken every day, according to the San Francisco AIDS Foundation. Promotion of its use in San Francisco has helped the city bring new cases of HIV to record lows.

For people without health insurance or those whose policies don’t cover the drug, out-of-pocket costs for PrEP can be as high as $13,000 a year, the AIDS foundation says. Use of PrEP has particularly lagged among Americans of color.

Besides requiring health insurance providers to pay for the drug, Harris’ bill would set up a grant program for states to help people without insurance get PrEP. It would also prohibit life and long-term-care insurance providers from denying certain forms of coverage or charging more to people who take the drug.

“PrEP is a critical advancement in the fight against HIV that can finally provide peace of mind to Americans who live in the shadow of the HIV epidemic,” Harris said. “But for too many in our country, lack of insurance coverage and exorbitant costs have put PrEP out of reach — and that needs to change.”

Lawmakers have introduced bills this year to fund grant programs for PrEP. But none of the bills has sought to ensure its coverage without cost to patients, and none has advanced. Harris’ bill will face long odds in the Republican-controlled Senate.

In California, state Sen. Scott Wiener, D-San Francisco, has proposed a bill that would provide people their first 30 days of PrEP over the counter if they receive counseling and an HIV test first. The bill passed the state Senate and is pending in the Assembly.

Tal Kopan is The San Francisco Chronicle’s Washington correspondent. Email: tal.kopan@sfchronicle.com Twitter: @talkopan