Is Medicaid expansion reducing SSI claims? If so, an uninsured diabetic in Tennessee called it

There is some evidence that the ACA's Medicaid expansion may be reducing claims for Supplemental Security Income (SSI). While such claims are dropping across the US as employment picks up, they're dropping somewhat faster in states that opted in to the ACA Medicaid expansion Modern Healthcare's Virgil Dickson reports:

The number of Americans applying for Supplemental Security Income benefits dropped in the first six months of this year compared to the same period last year, and experts are debating whether the decline is partly related to the healthcare reform law's Medicaid expansion to low-income adults.

A total of 1,189,567 SSI disability claims—mostly related to physical or mental disability— were filed in the first six months of 2014, compared with 1,330,169 during the same period last year, a drop of 10.6%, according to data obtained by Modern Healthcare from the Social Security Administration through a Freedom of Information Act request. The total decline in SSI claims in states that expanded Medicaid in the first six months of 2014 was 11.2%, compared with 10.0% in non-expansion states.

Back in June 2012, an uninsured diabetic waiting in line for treatment at a Remote Area Medical clinic in rural Tennessee forecast such a drop to New Republic reporter Alec MacGillis:

Will the 'doc fix' revolutionize U.S. healthcare?

I'm new to this, and so lack important context, but it looks to me as if a pending 'doc fix' -- a long-term replacement for the failed Medicare reimbursement formula (part of the Balanced Budget Act of 1997) that Congress patches up every year --could transform our healthcare delivery system at least as sweepingly as the Affordable Care Act.

Modern Healthcare's Rich Daly reports that two rival bills have been introduced. A bipartisan bill all but phases out fee-for-service, while a GOP bill preserves but modifies it. The first,  introduced by Rep Allyson Schwartz (D-Pa) and co-sponsored by Rep. Joe Heck (R-Nev.), an osteopath, is summarized by Daly as follows:

Schwartz's bill (PDF) would mostly unravel the fee-for-service system by requiring physicians to adopt one of several replacement models that the CMS would test and approve over five years. Physicians who did not do so would face successive payment cuts, although a small number of physicians could remain in a modified fee-for-service system if they met certain quality benchmarks or were near retirement.