This is just in the first seven months since the program's inception.
The full health benefits coverage for some adults ages 19-64 who earn too much to qualify for traditional Medicaid began on Dec. 1. This is roughly two months after lawmakers completed their last step to implement a deal available through the 2010 federal Affordable Care Act.
"For ten years, we fought to expand Medicaid," Cooper said Friday, "because we knew North Carolinians -- who were working sometimes two (or) three jobs -- that they were falling into that health insurance gap. We're the richest nation in the world. That's unacceptable. That's why Medicaid expansion is the working family's bill of the decade for North Carolina."
WATCH | Full video: Gov. Cooper announces 500K people now enrolled in Medicaid expansion program
Gov. Cooper announces 500K people now enrolled in Medicaid
According to Cooper, the initial goal was to sign up 600,000 people over two years.
Nearly 273,000 people, most of whom had been receiving Medicaid for family-planning coverage alone, were covered on the first day of enrollment. This number rose to 400,000 in the first four months.
North Carolina Department of Health and Human Services Secretary Kody Kinsley and other state leaders spoke alongside the governor.
"This is an amazing milestone for the people of North Carolina," Kinsley said. "We are not just getting people covered; we are getting people care."
He said the program has helped fill 1.9 million prescriptions, including ones for chronic conditions, seizures, and asthma.
During their fight for expansion, Cooper said he met many of those North Carolinians who fell into the coverage gap. They told their stories of hardness and illness, hoping it would make a difference.
"Well, it did," he continued. "It absolutely did...every person that reenrolled in Medicaid expansion is another person who can see a doctor when they are sick, who can continue being there in our strong North Carolina workforce, and provide for their family."