**2.4 Consolidation and growing market power**

Increasing consolidation through mergers within the private health insurance industry has taken place since the 1990s. The largest insurers today—in numeric order United Health Group, Anthem, Aetna and Cigna—collectively have a market share of 49% [10]. As a result, that level of consolidation has led to less competition, more cost sharing with higher deductibles, and less options for enrollees. United Health Group,


#### **Table 1.**

*Comparative features of privatized and public medicare (CAF Table 1.2, p. 14).*

as the largest insurer in the country, has also gained clout beyond insurance by selling technology to hospitals, managing clinical trials, distributing prescription drugs, and offering continuing medical education to physicians [11].
