Sarah Kliff, Forget the governors: Are doctors ready for the Medicaid expansion? (emphasis mine):

If [state governors] expand Medicaid, bringing 17 million new patients into the system, will there be enough doctors to see them? It’s one thing to give out new insurance cards. It’s quite another to ensure that the new card guarantees access to health-care providers.

The challenge is especially vexing in Medicaid, which tends to pay providers less than its sister program for the elderly, Medicare, and private insurance… In some states, Medicaid pays only 37 percent of Medicare’s rates.

Those low reimbursement rates are often cited as the reason that about a third of doctors say they are not accepting new Medicaid patients. One recent study found that two-thirds of Medicaid callers had trouble securing an appointment with a specialist, compared with 11 percent of private insurance subscribers.

How do we know that low reimbursement rates are the culprit? A Health Affairs study in 2012 showed some of the best evidence for this idea yet. It found a strong correlation between states that had low reimbursement rates  and a higher number of doctors who said they were not accepting new Medicaid patients.

That same study … also found that one-third of doctors nationwide said, in 2011, that they would not accept new patients.

This is the downside access landscape that governors are staring at when they think about expanding the Medicaid program: A program that pays lower rates, and has a not insignificant number of doctors who have ruled out new patients altogether.

The drafters of the Affordable Care Act did contemplate these challenges, and included some provisions meant to counter these exact types of access issues. While they didn’t expect that they would have to woo Republicans into participating in the Medicaid expansion, these parts of the law just might do the trick.

The health-care law’s big attempt at increasing Medicaid access takes on the exact same factor that we think inhibits access: Low reimbursement rates. The Affordable Care Act boosts Medicaid primary care reimbursement rates to match those paid by the Medicare program. Given that Medicaid rates tend to be really low, this works out to an average raise of 73 percent.

Does that matter on the ground, to providers? It’s hard to know from most of the Medicaid research, which was conducted before the Affordable Care Act expanded Medicaid. We do have one study … which suggests that most doctors do feel like they can take on more Medicaid patients than they currently see.

…

What they found was that, perhaps surprisingly, most doctors said yes: They were ready to take on more Medicaid patients. Eighty-one percent of primary care providers said they had the capacity to accept new patients. Those doctors were evenly distributed between … rural and urban areas.

…

“I think the facts speak for themselves,” [says the director of the Univ. of Michigan center which organized the study]. “Financially, the state comes out ahead, hundreds of thousands of citizens gain insurance and we have the provider capacity.”

There are still 17 governors still weighing their decisions, though — and whether their doctors are also ready could be a big factor in whether they say yes or no.

This is an element of the ACA that needs to work if it’s to be successful in its entirety.