In the largest-ever gift of its kind, a New York businessman is pledging millions toward improving health care services for people with intellectual disabilities.

Tom Golisano will give $12 million to Special Olympics to launch a major new health initiative in six states and seven countries. The founder of payroll processor Paychex, Golisano has given significant sums personally and through his foundation to organizations supporting those with developmental disabilities.

The donation, which will be spread out over four years, is the largest single gift from an individual in Special Olympics’ history. It was announced this week at the annual meeting of the Clinton Global Initiative.

The new funding will be used to establish an initiative dubbed “Healthy Communities” in Arizona, Florida, Kansas, New Jersey, Wisconsin and New York. Internationally, the program will also launch in Mexico, Peru, Romania, Malawi, South Africa, Malaysia and Thailand, officials said.

The plan calls for more than 1,500 clinics to be created specifically to address the health care needs of people with intellectual disabilities. Training will also be provided for 5,000 health care professionals on how to treat those with special needs.

The Healthy Communities program will build on Special Olympics’ existing Healthy Athletes initiative which provides free health screenings to individuals with intellectual disabilities.

“I am dismayed that people with intellectual disabilities and their health needs and status remain largely invisible to practitioners, systems, governments and larger global health community,” Golisano said, adding that he hopes to spur “sustainable, systemic change.”

According to Special Olympics, people with intellectual disabilities experience significantly higher rates of preventable illness as compared to the rest of the population. What’s more, research shows that those with disabilities often have trouble finding medical providers to meet their unique needs.