"Good cause" for remand due to Secretary's failure to develop record. ALJ is not at liberty to substitute his own impression of an individual's health for uncontroverted medical opinion. Given unchallenged diagnosis of chronic schizophrenia, coupled with uncontradicted testimony concerning claimant's degeneration in recent years and evidence of gross interference with his interpersonal relations, finding of no severe impairment was not supported by substantial evidence. If Secretary is doubtful as to severity of claimant's mental disorder, appropriate course is to request a consultative evaluation, not to rely on the lay impressions of the ALJ. ALJ incorrectly applied "Listing" standard at Step 2. Certain mental abilities are a prerequisite to working: the regulations suggest as prerequisite to working: the ability to understand, carry out and remember simple instructions, to use sound judgment, to respond appropriately to supervision, co-workers and usual work situations and to deal with changes in a routine work setting. While claimant bears the burden of proof on the issue of disability, the Secretary nonetheless retains a certain obligation to develop an adequate record from which a reasonable conclusion can be drawn.

ALJ may make common sense judgments about functional capacity based on medical findings as long as he does not overstep the bounds of a lay person's competence and render a medical judgment. Evidence regarding claimant's daily activities and demeanor at the hearing, plus doctor's findings of no consistent neurological deficit and no objective evidence of lumbo-sacral root syndrome, constitute substantial evidence to support the finding that claimant's pain, viewed as a non-exertional impairment, did not significantly impair claimant's ability to perform the full range of sedentary work. Whether or not a consultative report of a non-examining physician constitutes substantial evidence depends upon the circumstances of the case.

Vocatoinal Factors. Stress. "Stress is not a characteristic of a job, but instead reflects an individual's subjective response to a particular situation ... Without an evaluation of Lancellotta's vocational abilities in light of his anxiety disorder, there is no basis for the ALJ's conclusion that he can perform low stress work." Stress is a factor which must be considered on an individualized basis for performing a range of work at step 5. Vocational evidence that there are a significant number of jobs in the economy that would be "low stress" for the average worker falls short of the requirements of Ruling 85-15. ALJ must undertake subjective, individualized inquiry into what job attributes are likely to produce disabling stress in the claimant, and what, if any, jobs exist in the economy that do not possess these attributes. ALJ must make subjective, individualized inquiry into nature of and what triggers claimant's nonexertional limitations. ALJ erred by failing to make findings as to claimant's ability to perform basic mental work-related activities. Although the ALJ apparently relied upon claimant's even demeanor at the disability hearing as evidence of his ability generally to work at low-stress jobs, we consider a claimant's ability to visit doctors and describe his medical problems coherently as insufficient evidence of his ability to work. Hypothetical to vocational expert is inadequate because it failed to elicit from the vocational expert any testimony directed specifically to the conditions that are likely to produce stress in the claimant. The basic mental demands of competitive, remunerative, unskilled work include the abilities (on a sustained basis) to understand, carry out, and remember simple instructions; to respond appropriately to supervision, coworkers, and usual work situations; and to deal with changes in a routine work setting. A substantial loss of ability to meet any of these basic work- related activities would severely limit the potential occupational base. This, in turn, would justify a finding of disability because even favorable age, education, or work experience will not offset such a severely limited occupational base." Social Security Ruling 85-15. The burden of showing the existence of other jobs in the national economy that the claimant can perform (Step 5) rests on the Secretary. Vocational evidence that there are a significant number of jobs in the economy that would be "low stress" for the average worker falls short of the requirements of Ruling 85-15. ALJ must undertake subjective, individualized inquiry into what job attributes are likely to produce disabling stress in the claimant, and what, if any, jobs exist in the economy that do not possess these attributes.

At the hearing, claimant did not appear preoccupied with personal discomfort and his thoughts did not wander during the hearing. He answered questions alertly and his general appearance suggested no obvious abnormality." In reviewing the record for substantial evidence, "issues of credibility and the drawing of permissible inference from evidentiary facts are the prime responsibility of the Secretary."

ALJ is not qualified to interpret raw medical data in functional terms, but in this case, ALJ warranted in finding that claimant's physical impairments do not impose significant exertional limits without medical assessment of RFC. ALJ's observations at hearing were important Avery considerations in light of paucity of medical evidence. ALJ's observation of disability benefits claimant's demeanor at hearing provided substantial evidence for conclusion that nonexertional impairments did not disable claimant, in light of paucity of medical evidence to suggest objective physical basis for disabling pain and vocational expert testimony that claimant could perform the jobs he identified even if she suffered a constant light pain.