Back in February, I highlighted the fight to reauthorize Medicaid expansion under ObamaCare in Arkansas. The states’ plan not only expanded Medicaid; it did so in a more expensive way. Supporters claimed that the concerns were hogwash. Costs would be the same or lower because Department of Health and Human Services (HHS) required “budget neutrality” for the expansion. A new report from the Government Accountability Office (GAO) confirms that AR’s expansion is a budget-buster.

Medicaid provides insurance to low-income individuals, focused on pregnant women, children, and the disabled. ObamaCare sought to expand this program adding millions of able-bodied, childless adults to the program. States that agreed to dramatically expand the entitlement program would receive a large sum of federal funding. The federal government agreed to fund 100 percent of expenditures through 2016, slowly decreasing to 90 percent in 2020 and after. Even with the large financial enticement, states, rightly, resisted. The program is expensive to operate. States also have little control over the program. The quality of insurance is poor. A 2013 study found “no significant improvements” in health outcomes for individuals joining the program.

Arkansas decided to try something different. Under the plan passed by Democrat Governor Mike Beebe and the Republican legislature, more than 200,000 individuals would join the state’s Medicaid rolls. These individuals would not join the traditional program, but instead would receive money from the state and federal government to purchase insurance on the state’s newly-created health insurance exchange. This plan was preferable, according to advocates, because it would eliminate the known health disparities between traditional Medicaid and private insurance. Better yet, the AR Department of Human Services said that the so-called private option would save the state $670 million over the next ten years and would save the federal government $600 million. Choice and competition would power the market and result in lower prices.

Supporters argued that if the state was going to dramatically expand an entitlement program; it should do it in a fiscally-conservative way saving money in the process.

However, subsidizing Medicaid expansion through private insurance is not fiscally conservative. It turns out that private insurance costs $3,000–or 50 percent more–per enrollee than traditional Medicaid coverage according to the Congressional Budget Office (CBO). Spending $3,000 per person more adds up to a huge added cost for taxpayers. This would be compounded by the Arkansas’ decision–due to federal strings–to eliminate any out-of-pocket expenses for enrollees; no co-pays, no deductibles, no cost-sharing.

Supporters of Arkansas’ expansion claimed it didn’t matter because HHS’s approval required that the plan be “budget neutral.” In other words, the federal government would not spend more than if the state pursued traditional expansion. If the state exceeded the budget cap, the state would be responsible for the additional expenses. The state would be forced to tweak the program later if costs rose.

The plan passed and costs quickly grew. The first month was overbudget. As of June, the program was $10 million overbudget.

GAO now says that HHS did not guarantee budget neutrality in the Arkansas plan suggesting that even more taxpayer money is at risk. “HHS did not ensure budget neutrality. HHS approved a spending limit that included hypothetical costs despite questionable state assumptions and limited supporting documentation…HHS officially told us they accepted the state’s projections of the increased cost of expanding Medicaid in the absence of a demonstration without requesting data to support the state’s assumptions.”

HHS just accepted what Arkansas said, and did not question the state’s assumptions. The promised federal backstop does not seem to exist. GAO estimates that the “$4.0 billion spending limit approved by HHS was about $778 million [over three years] more than what it would have been.” That’s a 20 percent increase in costs for federal taxpayers.

Making matters worse, GAO says that AR has the authority to “adjust the approved spending limits if costs…prove higher than expected.” This sort of upward flexibility never used to be granted, but HHS recently granted it to 11 other states. AR has already acknowledged that it might need a higher spending limit.

This is not the first time that GAO has highlighted HHS’ inability to properly enforce budget neutrality. HHS’ refusal to properly set spending caps is costing federal taxpayers millions, or billions, more than it should. GAO confirms that Medicaid expansion in Arkansas is busting the budget.