FIGURE 2 Hypothetical distribution of disability for work among SSA claimants.

SSA’s existing data, data from the APA study, and findings of the National Academy of Social Insurance, it is possible to identify the major questions raised in the existing five-step sequential process and the proposed four-step sequential process:

• Imagine a bell shaped curve (Figure 2)—a normal distribution of disability for work—among SSA claimants. (It is not truly a normal distribution. SSA data can supply this information.)

• Bisect the curve with a perpendicular line. To the right of the line are those claimants who cannot work, who are disabled for work according to the SSA statutory definition. To the left are those who are not disabled for work.

The first step of claims for both SSDI and SSI benefits based on either mental or physical disorders in sequential evaluation decides whether the claimant is already working. These people are not processed beyond the DO and do not appear above. There are no plans to change the first step.

The second step in the existing sequential evaluation eliminates those with slight limitations (claimants at the far left on the curve). They represent an extreme and are easy to decide on medical evidence. This was not a problematic decision in the APA study. This step is accomplished using the B criteria on the PRTF. No such determination will be made in the proposed SSA revision. This group with slight limitations would be carried along the whole process. The Committee to Review SSA’s Disability Decision Process Research in its second interim report recommended that SSA should use a global functional assessment measure to screen out people who do not have severe disabilities (Wunderlich and Rice, 1998, p. 22).

The third step allows benefits to those who are so severely limited (those at the far right of the curve) according to the B criteria of the