Gain in Insurance Coverage and Residual Uninsurance Under the Affordable Care Act: Texas, 2013-2016.

OBJECTIVES: To examine the effects of the Affordable Care Act's (ACA's) Marketplace on Texas residents and determine which population subgroups benefited the most and which the least.

METHODS: We analyzed insurance coverage rates among nonelderly Texas adults using the Health Reform Monitoring Survey-Texas from September 2013, just before the first open enrollment period in the Marketplace, through March 2016.

RESULTS: Texas has experienced a roughly 6-percentage-point increase in insurance coverage (from 74.7% to 80.6%; P = .012) after implementation of the major insurance provisions of the ACA. The 4 subgroups with the largest increases in adjusted insurance coverage between 2013 and 2016 were persons aged 50 to 64 years (12.1 percentage points; P = .002), Hispanics (10.9 percentage points; P = .002), persons reporting fair or poor health status (10.2 percentage points; P = .038), and those with a high school diploma as their highest educational attainment (9.2 percentage points; P = .023).

CONCLUSIONS: Many population subgroups have benefited from the ACA's Marketplace, but approximately 3 million Texas residents still lack health coverage. Adopting the ACA's Medicaid expansion is a means to address the lack of coverage.