This document summarizes research on the effects of the Affordable Care Act's Medicaid expansion. It finds that the expansion led to 16.1 million more enrollees in Medicaid/CHIP, with about half due to newly eligible individuals and half from increased enrollment of previously eligible people. The expansion significantly reduced the uninsured rate for low-income adults and improved access to and affordability of care. Studies found expanded Medicaid improved quality of care, health outcomes, and prescription drug use. Private option plans had similar benefits as traditional Medicaid with few differences. The expansion also reduced uncompensated care costs for hospitals and had budgetary benefits for states. However, Medicaid expansion remains politically controversial, especially in non-expanding states in

1. Evidence on Medicaid and the ACA
Petrie-Flom Center
Benjamin Sommers, M.D., Ph.D.
Harvard T.H. Chan School of Public Health
December 2017

2. Plan for Today
• Short presentation on research evidence
to date on the ACA’s Medicaid expansion
• Effects of ACA’s Medicaid expansion:
– Patients
– Hospitals
– State budgets
– Alternative models of expansion
• Politics of Medicaid reform
2

3. Medicaid Expansion: Coverage
3
Source:
Sommers,
Gunja et al.,
JAMA 2015

4. Medicaid Expansion: Coverage
• CMS statistics:
– 16.1 million more enrollees in
Medicaid/CHIP as of 8-2016, compared to 9-
2013
• Survey estimates:
– Roughly half of gains were pre-ACA eligible
(‘woodwork’), other half were part of ‘early
expansions’ or 2014 newly-eligible
– Uninsured rate for low-income adults fell by
5.2 percentage points from expansion
4
Sources: CMS 2016; Sommers et al, JAMA 2015; Frean, Gruber, Sommers JHE 2017.

5. Medicaid Expansion:
Better Access & Affordability
5
Source: Commonwealth Fund, “In the Literature,”
Adapted from Sommers et al., JAMA Int Med 2016
Changes from 2013 to 2015 after Medicaid expansion in
two states (KY and AR), compared to no expansion (TX)

6. Quality of Care and Health
6
Source: Sommers, Orav, Blendon, & Epstein, JAMA Internal Medicine, 2016

7. Medicaid Expansion:
Increased Prescription Drug Use
7
Notes: “Rx per capita” is per non-elderly adult in the state (not just Medicaid beneficiaries).
Source: Ghosh, Simon, and Sommers 2017 NBER Working Paper

8. Private Option vs. Medicaid:
Both Beneficial, Few Differences
-35% -25% -15% -5% 5% 15%
Excellent self-reported health
Fair/Poor quality care
Diabetics Glucose Check
Check-up
Regular care for chronic conditions
Annual out-of-pocket spending*
Trouble paying medical bills
ED is usual source of care
Skipped prescription due to cost
Cost-related delay in care
Personal doctor
Usual source of care
Medicaid
Private Insurance
Uninsured
MEDICAID EXPANSION PRIVATE OPTION
Notes: Bars show difference-in-differences comparison, relative to non-expansion (Texas).
* Outcome is Log(Spending), with estimate reported as percent change. All other estimates are percentage-
points.
P-value,
AR vs. KY
0.28
<0.001***
<0.001***
0.08*
0.08*
0.26
0.99
0.22
0.33
0.05**
0.50
0.49
0.05**
0.42
0.94
Source: Sommers et al. JAMA Internal Medicine, 2016

9. Medicaid Expansion:
Reduced Hospital Uncompensated Care
9
Source: Nikpay et al. Health Affairs, 2016

10. Expansion Budget Effects
10Source: Sommers & Gruber, Health Affairs 2017

11. Budget Effects, FY 2010-2015
11Source: Sommers & Gruber, Health Affairs 2017

12. Red States and ACA Repeal
12
0%
5%
10%
15%
20%
25%
30%
35%
40%
45%
Arkansas Kentucky Louisiana Texas
Helped by ACA
Hurt by ACA
1,570 adults 19-64 with incomes < 138% of poverty were asked in Nov-Dec 2016:
“So far, would you say the health care law has directly helped you, directly hurt
you, or has it not had a direct impact?” Source: Sommers & Epstein, NEJM 2017

13. Medicaid is Actually Popular
13
Source: Barnett & Sommers JAMA IM 2017 – using National Medicaid CAHPS
Medicaid Enrollees’ Health Care Satisfaction Ratings, 2014-2015

14. Thank you!
14