The United States Senate is deliberating a bill that would repeal and replace the Affordable Care Act, and a study by an assistant professor in the University of Maryland's public health school shed light on the ACA's effect on low- and moderate-income families.

Michel Boudreaux, first author of the study, said the ACA reduced the amount of individuals under 65 in the individual insurance market who spent more than 10 percent of their income on health care. Those in the individual insurance market purchase their insurance directly through insurance companies, rather than receiving it through their employer or public coverage like Medicaid.

"Under the ACA, subsidies varied by income and by how much your premiums actually cost," Boudreaux said. "The goal there was to make sure that people who had low and moderate incomes would not have to pay more than a certain portion of their income on health care costs."

The study found the average rate of financial burden for those in the individual insurance market decreased 6.7 percent from 2013 to 2015, and was reduced by 10 percent for those with incomes at or below four times the federal poverty level, who received subsidies in the individual insurance market thanks to the ACA. Average annual spending for those in the individual insurance market also declined by $800, according to the study.

The study also found a statistically significant reduction in the amount spent by those in the individual insurance market on premiums and out-of-pocket costs in 2015 compared to 2013. The individual insurance market included 5 percent of those under 65 in 2013, and 7.5 percent in 2015.

Although the total spending in 2015 for those in the individual market was down from 2013, the study showed total spending for the same group was actually up from 2014. In addition, the study said "a small but significant increase of $159 in total family medical spending from 2013 to 2015" was found, despite a reduction in out-of-pocket spending from 2013 to 2014. Boudreaux said the individual market might not be worse off with the AHCA than it was before the ACA.

The American Health Care Act, which was voted on by the House of Representatives and sent to the Senate on May 4, would introduce major changes to the tax credit system and other facets of the ACA that helped reduce the financial burden for people in the individual insurance market. The Congressional Budget Office estimates that 14 million more people would be uninsured under the legislation than under current law. Most of that increase would come from repealing the penalties associated with the individual mandate, according to their website.

Dylan Roby, assistant professor of health services administration, said one such change would have subsidies for health insurance be determined by age, rather than income. Under the AHCA, he said, young people would receive $2,000 to help them buy insurance, but older people would get $4,000 despite the elderly often paying more than younger people for health care.

"Some people are going to be better off, and some people are going to be worse off. Young healthy people might see lower costs, but older sicker people are going to see much higher costs," Boudreaux said.

The AHCA could impact college students, Roby said.

"If the federal government changes the Medicaid rules so the per capita cap payment instead of the matching formula is used to fund Medicaid, states could then be incentivized to then change the eligibility rules, create exclusions, create work requirements, all these other things that hurt students' ability to qualify for Medicaid even if they're low income," Roby said.

Although the ACA's provision allowing individuals up to the age of 26 to remain on their parents' health care plans is not directly changed by the AHCA, Roby says the bill could indirectly affect those under 26 who are on their parents' plans. He said 55 percent of the population receives their insurance through employers, and the AHCA would allow employers to choose a benefit package, which says how much the insurance plan covers, from any state. If an employer wanted to save money, they could use a benefit package from a state that is more relaxed in its package regulations.

"If the ACA is repealed and/or replaced, we anticipate that more students may enroll in SHIP [Student Health Insurance Plan]… If fewer students have access to good coverage through their families or as a result of Medicaid expansion because of changes in the ACA, more will likely enroll in the affordable and very comprehensive coverage of SHIP," wrote David McBride, director of the university Health Center, in an email.

The proposed tax credit system also doesn't consider how much premiums cost depending on location, Boudreaux said, which will result in those living in states with low premium costs benefiting more than those in places like Alaska where the cost of health care is much higher.

Boudreaux said the bill would let states decide if they will allow insurance companies to charge individuals with pre-existing conditions more by putting them in "high-risk pools," which he said have been shown to not provide the sick with proper medical care and are not allowed under the ACA. The bill would also reduce Medicaid spending by $840 billion over the next 10 years, which he said would have a much larger effect on people's ability to receive health care than the tax credit changes.

He said that under the ACA's current matching percentage, the federal government agrees to pay a certain percentage of each state's health care costs regardless of how many individuals signed up for Medicaid or how much care they used. Under the AHCA, a per capita cap on health care payments would be implemented, effectively giving each state a flat dollar amount for each person enrolled in Medicaid and expecting the states to pay for the rest of the costs on their own. To pay for the costs and balance their budgets, Boudreaux said, states will be forced to reduce the amount of care given to people.

Roby said the AHCA is unlikely to pass in the Senate. The AHCA is being moved through the budget reconciliation process, which allows for expedited consideration of certain tax, spending and debt limit legislation. This means the bill cannot be filibustered. Republican Congressmen are pursuing this method because they do not have the required 60 votes to prevent the bill from being filibustered. As part of the budget reconciliation process the bill can only change things relevant to the budget in terms of additional tax revenue or spending.

"There are a bunch of things in the AHCA that can make it through the House because they don't have those filibuster rules, but won't make it through the Senate because the Parliamentarian will say it's not relevant to the budget," Roby said.