Jagadeesh Gokhale of the Cato Institute takes on the issue:

According to the Social Security Trustees, the program’s trust fund will be fully depleted in 2016, compelling either a large benefit cut or a large tax hike—neither option being politically popular. Regardless of the program’s insolvency, SSDI creates substantial work disincentives, causing many with medical impairments who could work to withdraw from the labor force and apply for SSDI. . . .
Many beneficiaries express a desire to return to work but fear of losing benefits and health coverage under SSDI’s current benefit rules impedes such a decision. . . . Shifting benefits at the margin toward paying beneficiaries to work rather than to remain out of the work force would encourage beneficiaries with residual work capacities to return to work. That shift would serve as a backstop to reduce the economic loss from wrongful allowances of applicants into SSDI. Such a switch in benefit design can be accomplished without compromising benefit eligibility for those who cannot work.

Sounds like a good idea to me.