Vocational counselors have recently been employed as expert witnesses in processing claims for disability insurance under Section 216 (I) and Section 223 of the Social Security Act. This article describes the hearings process and demonstrates how the vocational counselor prepares to express an opinion as to whether or not a claimant for disability insurance has shown a residual capacity to function satisfactorily on a sustained basis in our economy. The opinion of the consultant is based on the file of official exhibits and testimony. During the hearing, the consultant's opinion is supported by reference to the specific tools of his profession. The consultant may modify his opinions as a result of testimony elicited during the hearing. The counselor not only states that the claimant can function satisfactorily in competitve work but he also mentions specific jobs which are within the claimant's residual capacities. On the other hand, if it is his opinion that the claimant cannot work, he must support his opinion with a sound rationale.