The Affordable Care Act, passed in 2010, originally mandated that Medicaid would be expanded nationwide to include all adults with annual incomes at or below 138 percent of the poverty line, or slightly more than $16,000. But the 2012 Supreme Court decision upholding most of the ACA's legality also said that the decision on whether to expand eligibility for Medicaid recipients would be left up to individual states.
As of last fall, at the time of the launch of the Obamacare private insurance exchanges, about half the states had expanded Medicaid eligibility, but a number of them with Republican governors, whose party members tend to oppose the ACA, did not.
A majority of the states that expanded Medicaid have seen double-digit percentage growth in the program's enrollment rolls since then, with Oregon leading the pack with a nearly 44 percent spike in its enrollment, followed by West Virginia with 38.5 percent.
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While states that didn't expand Medicaid weren't expected to see such large increases, the fact that 17 of them did see gains is a reflection of the impact of Obamacare-related outreach and awareness, said Avalere Health CEO Daniel Mendelson.
"This is the educational effect of HealthCare.gov," Mendelson said. HealthCare.gov is the Obamacare enrollment website that handles health insurance sign-ups for residents of 36 states not running their own exchanges.
After people create accounts on that site, HealthCare.gov informs them whether their incomes are low enough to qualify them for Medicaid, or whether they need to purchase private insurance plans to meet Obamacare's mandate to have health insurance.
"There's low-income people who get online, and lo and behold they have the shock of their week and find out they're eligible for Medicaid," Mendelson said. "Some of them probably are a little bit mortified because there's a stigma associated with Medicaid in many populations, but they sign up anyway because it's cheaper."
Still, Mendelson noted, "there are millions of people who are eligible for benefits that have not signed up for them."
"It's really hard to get everybody. There are language issues, there are cultural issues ... there are issues related to poverty," he said. "Stigma is another one."
Robin Rudowitz, an associate director of the Kaiser Family Foundation, said it is difficult to identify one single factor that led to most of the woodworking enrollment.
Rudowitz noted that in addition to increased outreach and awareness associated with Obamacare, the ACA mandated that all states modernize and simplify their Medicaid enrollment processes so that people could sign up in a variety of ways, and quickly learn whether they are eligible for coverage. That simplification also played a role in boosting enrollment numbers, she said.