The authors convened three panels of physicians to rate the appropriateness of a large number of indications for performing a total of six medical and surgical procedures. The panels followed a modified Delphi process. Panelists separately assigned initial ratings, then met in Santa Monica, California, where they received reports showing their initial ratings and the distribution of the other panelists' ratings. They discussed the indications and revised the indications lists, then individually assigned final ratings. There was generally better agreement on the final ratings than on the initial ratings. Based on reasonable criteria for agreement and disagreement, and excluding one outlying procedure, the panelists agreed on ratings for 42 to 56 percent of the indications, and disagreed on 11 to 29 percent.