ACA Marketplace premiums and competition among hospitals and physician practices.

To examine the association between annual premiums for health plans available in Federally Facilitated Marketplaces (FFMs) and the extent of competition and integration among physicians and hospitals, as well as the number of insurers.We used observational data from the Center for Consumer Information and Insurance Oversight on the annual premiums and other characteristics of plans, matched to measures of physician, hospital, and insurer market competitiveness and other characteristics of 411 rating areas in the 37 FFMs.We estimated multivariate models of the relationship between annual premiums and Herfindahl-Hirschman indices of hospitals and physician practices, controlling for the number of insurers, the extent of physician-hospital integration, and other plan and rating area characteristics.Premiums for Marketplace plans were higher in rating areas in which physician, hospital, and insurance markets were less competitive. An increase from the 10th to the 90th percentile of physician concentration and hospital concentration was associated with increases of $393 and $189, respectively, in annual premiums for the Silver plan with the second lowest cost. A similar increase in the number of insurers was associated with a $421 decrease in premiums. Physician-hospital integration was not significantly associated with premiums.Premiums for FFM plans were higher in markets with greater concentrations of hospitals and physicians but fewer insurers. Higher premiums make health insurance less affordable for people purchasing unsubsidized coverage and raise the cost of Marketplace premium tax credits to the government.

Duke Scholars

Author M. Kate Bundorf Sanford School of Public Policy