All corners of the United States help headline a new poll from Gallup that examines changes to uninsured rates since January 2014, when PPACA's individual mandate provision took effect. Arkansas and Kentucky saw the sharpest decline in uninsured adult residents, with decreases of 10.1 and 8.5 percent respectively. Rounding out the top five states were Delaware (a -7.2 percent change), Washington state (-6.1 percent) and Colorado (-6.0 percent).

These states may span the length of a U.S. map, but they do have a few commonalities: All five chose to expand Medicaid, and four of the five set up their own state-based health insurance exchanges. (Arkansas has a state-federal partnership exchange.) Across the board, states that enacted both of these measures have seen a steeper decline in uninsured rates than states that have not: 4 percent across 21 states versus just 2.2 percent across the 29 states that either host a federal exchange or have declined to expand Medicaid.

These improved insured rates come at a cost, of course. A primary objection for states that have chosen not to expand Medicaid is the massive amount of resources a more robust program will consume. States like Utah have negotiations underway with the Centers for Medicare and Medicaid Services (CMS) to reach more flexible terms for what an expanded program might look like. If a solution is reached, it may help serve as a blueprint for other states reluctant to commit to the expense of more Medicaid enrollees, but eager to provide improved access to healthcare.