Ripples in the ACA risk pool

When a state that initially refused to implement the ACA Medicaid expansion embraces it, that's great news for state residents who were in the so-called "coverage gap" -- earning too little to qualify for subsidized private plans in the ACA marketplace, but denied the Medicaid coverage which the ACA had originally mandated for them, before the Supreme Court rendered the expansion optional for the states.

For another income group, those with household incomes between 100% and 138% of the Federal Poverty Level (FPL), the expansion may be a blessing for some but not all. People in this income range are eligible for subsidized private plans in states that have refused the Medicaid expansion -- but for Medicaid only in states that implement it.

As of the end of the ACA's last "open season" enrollment period in February 2015, 22 states had not yet adopted the law's Medicaid expansion, and one state, Indiana, had just adopted it, effective February 1.  In those states, about one third of enrollees in private health plans purchased in the ACA marketplace had incomes in the 100-138% FPL range and so would have been eligible for Medicaid if their states had embraced the expansion.  They constitute perhaps 15-20% of all enrollees in the ACA private plan plan marketplace.

Utah and Alaska are on course to expand Medicaid. Are their eligibility estimates inflated? (Updated)

Both Alaska and Utah seem to be on course to implement the ACA Medicaid expansion. In Alaska, Governor Bill Walker is asserting his authority to do so without the approval of the legislature. In Utah, Governor Gary Herbert has struck a deal with legislative leaders -- still perhaps facing a rocky course toward legislative approval -- to seek a waiver for a "private option" form of the expansion.

In both states, as in any state, pro and con arguments over expansion are based on cost estimates which are in turn based on estimates of how many state residents will gain eligibility for Medicaid. It's noteworthy that in both states, in 2015, the Kaiser Family Foundation radically cut its 2014 estimate of those in the "coverage gap" -- that is, those whose incomes would have qualified them for Medicaid had their states accepted the expansion but are too low to qualify them for subsidized private plan coverage on ACA exchanges.*

In Alaska, Kaiser's estimate of the Medicaid gap population shrank from 17,290 as of March 31, 2014 to 10,500 as of  April 17 of this year. In Utah, the drop was from 57,850 in 2014 to 30,000 in 2015. These estimate cuts are mainly due to a redesign of insurance questions in the Census Bureau's Current Population Survey, intended to address previous under-reporting of respondents' insurance coverage.** While Kaiser cut its estimates for every state, the reductions in Utah and Alaska were far and away the largest. In both states, though, state officials' estimates of the "gap" population are closer to Kaiser's earlier estimates than to the newly reduced ones. In both states, in fact, working estimates are higher than Kaiser's 2014 figures.