Both versions of the Republican health care plan would cut federal spending on Medicaid.

The Affordable Care Act expanded Medicaid, the government health plan for low-income and disabled people, by raising the income qualifications.

That could be rolled back or left to the states to pay for if either version of the American Healthcare Act becomes law.

If that happens, Colorado would need to find $385 million a year by 2021 and $677 million by 2023 to keep everyone currently enrolled on their plans, according to the Center on Budget and Policy Priorities.

To understand what that might mean for the 400,000 Coloradans who got coverage under the Medicaid expansion, 9NEWS turned to the Health District of Northern Larimer County.

The agency randomly sends a detailed survey to about 2,800 members every three years.

“We do a large community health survey because our mission is to improve the health of the community, and we feel like we can’t do that if we don’t track indicators over time,” said Carol Plock, the district’s executive director.

As far as she knows it’s the only one of its kind in Colorado.

And it just so happens that went out in 2013 and 2016 – creating a snapshot of healthcare in Colorado from before and after the Medicaid expansion.

“Usually when we survey people we see changes from three years to three years, but we see modest changes,” Plock said. “But this year we were really surprised to find some eye-popping changes in people’s answers between 2013 and 2016. It was far more dramatic than we usually see.”

Plock saw the number of people in the district without health insurance drop from one in eight to one in 25.

“And if you think of any group you’re in, and you count one in eight compared to one in 25, that’s like a huge difference,” Plock said. “It’s a decrease of almost two thirds.”

But the biggest changes were the responses from the people earning 138 percent of the federal poverty level or below – the people who qualified for Medicaid under the Obamacare expansion.

Survey respondents in that group were 60 percent less likely to forego a mental health visit because they couldn’t afford it. And the percentage of people who skipped filling a prescription was cut in half.

“And if you think about it, mental health and prescriptions services, both of them are critical for health, but they are also critical for self-sufficiency,” Plock said. “So, that's an incredible finding.”

It also kept some people out of financial trouble.

The Larimer county survey found a 34 percent decrease in the number of people whose medical bills went to collections.

“So, obviously, some of the biggest changes are for those with the lowest incomes, but what was very interesting to us is we found that many of the changes extended way into middle income,” Plock said.

Respondents who earned between 139 and 250 percent of the federal income poverty level were less likely to put off going to the dentist or face a medical they couldn’t pay upfront.

But not everything got better in the last three years.

People in the middle-income bracket were more likely to put off going to a health care provider due to cost.

And people in the upper income group, 400 percent of the federal poverty level and above, experienced were more likely to be unable to fill a prescription due to cost.

Plock said the district isn’t taking a side in the health care debate.

“What we do feel like is it’s really important for our policy makers to understand the impact of the policies that we make. The impact on coverage, on care, on financial security,” Plock said. “And we’re hoping that they look for policies that help move everyone forward and not backward in having access to health care.”

9NEWS asked Republican and Democratic leadership in the Colorado Senate whether the state could or would potentially absorb the costs of keeping the Medicaid expansion, but we didn’t hear back at the time of this writing.