Exhibit 1. Characteristics of ACOs that serve high proportions of racial and ethnic minority patients compared to other ACOs.

Descriptive characteristics of ACOs that are high proportion racial and ethnic minority patients (75^th percentile or above) compared to lower proportion minority (all other ACOs); data from the Medicare and Medicaid Services Shared Savings Program ACO Public Use File, authors’ calculations

	High minority (N=81) Mean	Other ACO (N=250) Mean	Significance
Patient Characteristics
Proportion minority beneficiaries	0.40	0.11	****
Proportion under age 65	0.23	0.16	****
Proportion age 85 and older	0.12	0.12
Proportion dual eligible beneficiaries	0.18	0.05	****
Proportion disabled beneficiaries	0.20	0.14	****
Proportion female beneficiaries	0.56	0.54	***
Proportion ESRD beneficiaries	0.02	0.01	****
HCC for aged non-dual	1.15	1.05	****
HCC for aged dual	1.05	1.05
HCC for disabled	1.20	1.10	****
Physicians
Total providers (physicians, nurse practitioners, physician assistants, and clinical nurse specialists)	384	462
Proportion of providers that are primary care physicians	0.45	0.42

Source: Authors’ analysis of Centers for Medicare and Medicaid Services Shared Savings Program ACO Public Use Files, 2013 and 2014 (see Notes 24 and 25 in the text).

Notes: ACOs that serve high proportions of racial and ethnic minorities are in the 75^th percentile or above. ESRD is end stage renal disease. HCC is hierarchical condition category.

^*p < 0.10

^**p < 0.05

^***p < 0.01

^****p < 0.001