- An updated report from the Government Accountability Office found enrollment in private insurance was concentrated among a "small number" of payers in 2015 and 2016, with the three biggest payers owning 80% of private plans in at least 37 states.
- The Affordable Care Act exchanges were even more concentrated. As of 2017, three or fewer payers owned 80% of the individual market in at least 46 state exchanges. Small group was similarly concentrated in at least 42 state exchanges.
- Concentration increased since GAO's report on 2014 data. The latest report found the largest payers seized more market share in about two-thirds of ACA exchanges, due in part to consolidation and payers dropping out of the exchanges altogether.
Concentration is often the result of big mergers and acquisitions that end up squeezing small companies out of the market.
But the real victims of insurance consolidation are patients, often forced to choose between being uninsured or paying high premiums for less coverage.
A Gallup poll published in January found the uninsured rate reached 13.7% in the fourth quarter of 2018, the highest its been since the implementation of the individual mandate. The GAO published a separate report in January in which insurers projected a continued increase in premiums due to higher costs of care and the elimination of several ACA programs designed to mitigate risk and subsidize costs.
The administration's attempts to repeal the ACA created a lot of instability for payers, a few of which exited exchanges entirely. Humana, for example, dropped out of the individual market in 2018. In some cases, GAO found state ACA exchanges experienced drastic increases in concentration. For example, three of the biggest payers in Wisconsin collectively owned 92% of the state's exchange market.
States where competition is plentiful were not exempt from high concentration, according to GAO. In West Virginia, where 15 payers operate, Highmark held 91% market share. GAO found that single private payers owned at least 50% market share in 28 states in 2016.
Market domination is becoming a legacy trend in most states, with the single largest payers having held their majority shares in 35 states since 2011.
The fourth quarter of 2018 and recent findings from Kaiser and Urban Institute, however, signal that the tides may be turning for payers. Some are beginning to return to the market exchanges while others are finding profitability in new payment models such as narrow provider networks, which help reduce risk and contain costs, despite limiting patient options.
Correction: An earlier version of this story misstated Oscar's footprint in Florida.