In regions of the United States where health insurer market concentration is high, provider organization payment rates are lower than in regions with lower health plan concentration. Between 2010 and 2014 average hospital admission costs were 5% lower in highly concentrated insurer markets than in less concentrated markets due to insurer bargaining power. During the same period, in highly concentrated markets compared to less concentrated markets, insurers negotiated lower average office visit costs for cardiologists (4% less), hematologists (7% less), and oncologists (19% less). These findings were reported in “Insurer Market Power Lowers Prices In Numerous Concentrated Provider Markets” by . . .