The leading "Medicaid Transformation" proposal in the Missouri House purports to deliver a Medicaid expansion that effectively makes the state money. Suffice to say, that's a highly questionable claim, and I don't even have to cut apart any of the bill's dubious calculations to reach a very different conclusion. Why? The issue is startlingly simple: The bill's proponents simply did not account for more than half of the new costs of the Medicaid expansion.

Let me explain how that happened. There are two populations that we discuss regarding Obamacare's Medicaid expansion. The more obvious of the two is the population that would become "newly eligible" under the law — those who, by virtue of the law's passage, would now qualify for Medicaid coverage up to 133 percent of the federal poverty level. The Kaiser Family Foundation (KFF) estimated that had Missouri expanded its broken Medicaid program after the law passed, the newly eligible population would have cost the state more than a billion dollars from 2013 to 2022. The House expansion bill's hypothetical budget only really integrates that group into its calculation starting in 2015.

It's the second population, however, that is an even bigger budgetary concern, and it is substantively ignored in the expansion bill. That group is the "currently eligible" population: those who currently qualify for Medicaid but only become enrolled as part of the expansion's enrollment push. The phenomenon is sometimes called the "woodwork effect," as this population that has always been eligible emerges and begins leveraging the Medicaid entitlement for the first time. KFF estimated that over that same period, Missouri would pay $1.6 billion for those new enrollees. That's more than a doubling of the expansion's total costs. Without even addressing any of the other problems in the bill's budgetary forecast, how would the state pay the currently eligible cost of the expansion? I haven't heard an answer to that question for years now.

So far without expansion, Medicaid enrollment in Missouri has actually declined; under the circumstances, it is reasonable to suggest that implementation of the expansion itself would initiate the uptick in woodwork costs that KFF forecasted. It is inexcusable that these costs have not been accounted for in the House proposal, but rest assured, this isn't the first Medicaid expansion proposal I've read that failed to integrate these expenses.

Spending is no substitute for reform of a thoroughly broken Medicaid program, especially when the forecasted costs are so woefully understated. If it wasn't clear before, it should be now: reform is where the legislature should focus its attention, particularly this late in the session.