Exploring Associations Between 340B Participation and Hospital Consolidation

We examined associations between hospital system market share, merger activity, 340B participation and operating margins using data for 2,226 U.S. hospitals. We calculated Metropolitan Statistical Area (MSA)-level health system market share, tracked merger activity from 2017 to 2022, and constructed a commercial price index for 1,336 hospitals with available prices. Hospitals with a greater share were significantly more likely to participate in the 340B Program. Among larger hospitals, a 20 percentage-point increase in MSA-level health system share was associated with a 7.6 percentage-point increase in the likelihood of participation. Recent mergers were linked to an 8.6 percentage-point higher likelihood of 340B participation; 340B participation was associated with 1.1-3.0 percentage-point higher margins for non-merged hospitals and 5.2-7.0 percentage-point higher margins for merged hospitals. Greater market share and outpatient revenues were associated with larger estimated 340B margin effects, consistent with the outpatient-focused design of the program.