Court gives qualified approval to Grids as valid exercise of Secretary's statutory authority. Secretary may, using Grids, take administrative notice that substantial gainful work existed in the national economy for a person with claimant's impairment, background, age and education. Where a claimant presents a prima facie case of disability-i. e., that he can not engage in his previous type of employment-it is the Secretary's responsibility to establish that the claimant can engage in alternate employment and that such employment exists.

Approves administrative notice of occupational reference materials for information regarding various types of work. Court notes that the 4th circuit has held that the Secretary may rely on general categories in the Supplement to the DOT as presumptively applicable to the claimant's past work. Claimant's burden to prove an inability to perform her former type of work. necessarily includes an obligation to produce evidence on that issue. Claimant must not only show that she cannot do her former job, she must demonstrate that she cannot return to her former type of work. Opinions of non-examining consulting physicians are entitled to weight. Physician's conclusory statements about claimant's disability not binding on Secretary. The Secretary can rely on a job held more than 10 years ago in determining whether claimant can return to prior work. In order to meet burden at step 4, claimant must establish that she cannot return to her former type of work, not just her inability to return to a particular past job.

ALJ can base adverse decision on claimant's ability to do past work which claimant did more than 15 years ago, the 15 year limit applies only to transferability under a grid analysis, and the grid comes into play only after a finding that the claimant cannot perform past work.

At Step 4, the ALJ is entitled to credit the claimant's own description of her past work and her functional limitations, but the ALJ has some burden independently to develop the record. Citing Santiago, 944 F.2d 1 (1st Cir. 1991). Remand. Illegibility of non-trivial parts of medical record, combined with identifiable diagnoses and symptoms indicating more than a mild impairment, alerted ALJ to need for expert guidance regarding the extent of the claimant's RFC to perform her past employment. Case remanded. With a few exceptions, an ALJ, as a lay person, is not qualified to interpret raw data in a medical record. Where claimant sufficiently put her inability to perform her past work in issue, the ALJ must measure the claimant's capabilities, and ordinarily an expert's RFC evaluation is essential unless the extent of functional loss, and its effect on job performance, would be apparent even to a lay person. Ventricular tachycardia, frequent PVCs, sinus tachycardia, arterial hypertension

Environmental Conditions at Work. At Step 4, the claimant bears the burden of showing that he cannot return to his previous work. At Step 5, the burden shifts to the Secretary to show the existence of other jobs in the national economy that the claimant can nonetheless perform. To meet her initial burden it was not enough for claimant to show simply that her specific job as an illustrator entailed exposure to smoke and fumes; she would have to show that such exposure would be a condition of this sort of work generally. Remand where the record shows no meaningful inquiry by the ALJ into whether or not it the claimant could engage in her former type of work, technical illustration, without exposure to substances to which claimant is allergic. Although claimant did not raise the issue at the hearing, her original written application for disability stated that she was allergic to rubber cement, paint thinner, and fixative sprays and that the latter two items are used in art departments.

Transportation to Work. At Step 4, test is whether claimant has ability to return to past relevant work performed at substantial gainful activity level. Past insubstantial activity cannot demonstrate an ability to perform SGA. Available at DLC. Deference owed to ALJ’s credibility determination, but Appeals Council can overturn ALJ credibility determination if not supported by substantial evidence. Remand. Eligibility for Disabled Adult Child benefits requires that disability began before age 22 and continued until 6 months prior to application for benefits. Past insubstantial work cannot demonstrate an ability to perform SGA. Secretary's conclusion that claimant with schizophrenia is not disabled is not supported by substantial evidence. Claimant's ability to travel is "weak evidence" of a capacity to work, especially in light of repeated hospitalizations. The conclusions of two doctors that claimant can work are not persuasive, when the doctors' analysis consist of "four checkmarks on a standard form with an additional line or two of 'comments' at the bottom."

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.