SIOUX FALLS, S.D. (AP) – South Dakota philanthropist Denny Sanford is donating $25 million to help veterans determine which medications are most effective for them.

The U.S. Department of Veterans Affairs and Sanford Health announced the gift Tuesday. Veterans Affairs will administer what will be the nation’s largest pharmacogenetic testing effort. It’s expected to reach up to 250,000 veterans at 125 sites by 2022.

The testing program, at no cost to veterans, will launch this year at a pilot site in Durham, North Carolina and will initially enroll cancer survivors.

Pharmacogenetic testing helps doctors make decisions on what to prescribe for pain management, diseases and mental health issues. The $25 million gift will be paired with a matching fundraising effort by Sanford Health.

AP-WF-03-12-19 1436GMT