Using expert panels of medical technologists and public health microbiologists, a modified nominal group process was used to reach a consensus on three questions concerning current human immunodeficiency virus type 1 (HIV-1) testing methods. The questions related to important sources of error, improving the testing process, and improving proficiency testing. The modified nominal group process proved to be effective in developing lists of errors in laboratory testing; it provided a fast, economic means of identifying possible areas for improving laboratory quality assurance and training programs. For the HIV testing model, the focus group panelists indicated laboratory pipetting errors, labeling, and specimen identification as the most important sources of error. To improve the quality of this testing, the panel recommended standardizing test interpretation and restricting testing to laboratories licensed to perform HIV-1 testing. To improve proficiency testing, the use of blind specimens and establishing minimum standards of performance were suggested.