Santiago V. Sec'y HHS

At Step 4, claimant will be found not disabled when she retains the RFC to perform the actual functional demands and job duties of a particular past relevant job, as she performed it. The claimant is the primary source for vocational documentation. It's claimant's duty to describe her impairments so as to raise the point to the Commissioner how the impairments preclude the performance of her prior work. Where the testimony and evidence did not go far enough to raise a "meaningful issue" in regard to how claimant's impairments affected her ability to work, the ALJ had no duty to further develop the record by obtaining RFC assessments.