Anatomy Of A Slowdown: Decomposing The Moderation In Health Spending Growth, 2009–19

National health expenditure growth between 2009 and 2019 slowed to less than half the historical rate of growth seen between 1970 and 2008. To identify why, we gathered actuarial projections of the fiscal effects of policies implemented between 2009 and 2019, netted these out from the 2009 Centers for Medicare and Medicaid Services baseline projections of national health expenditures, and decomposed the residual differences by payer and service to shed light on the spending slowdown. We identified four trends that contributed to spending growth below the baseline projections: declining utilization and substitution of lower-cost alternatives across hospitals, physicians, and pharmaceuticals; slow private hospital and physician price growth and the expanding scope of practice of nonphysicians in office-based settings; declining home health use among the oldest Medicaid beneficiaries; and slow growth in private insurers' administrative spending. Our results raise questions about several of the assumptions that underlay previous forecasts of future health care spending.