Objectives To investigate the quality and completeness of economic models submitted by pharmaceutical manufacturers to health plans under the Academy of Managed Care Pharmacy (AMCP) Format for formulary submissions, and to compare economic models of “me-too” versus drugs judged to have significant competitive edge. Methods We analyzed economic models included in AMCP-Format dossiers submitted by pharmaceutical companies to the pharmacy services staff of Premera Blue Cross (Mountlake Terrace, WA, enrollment 1.5 million) in 2003. ‘Economic models' were defined as mathematical simulations that combined clinical and cost data to estimate the economic value of a drug. We assessed models' compliance with criteria recommended by the Panel on Cost-Effectiveness in Health and Medicine, including: justification of model type; statement of time horizon and discount rate; discussion and reporting of productivity changes; separate reporting of resource quantities from prices; comparison against relevant alternatives; reports of incremental results, sensitivity analysis, and mention of caveats. Outright budget impact models were not evaluated. Results Of 35 dossiers submitted during 2003, 27 (77%) included economic models. Of these, model type was justified in 8 (29%); time horizon stated in 22 (82%); discount rate stated in 5 (19%); relevance of productivity changes discussed in 1 (4%) but reported in none; resource quantities reported separately in 3 (11%); relevant alternatives compared in 11 (41%); incremental results reported in 5 (19%); some form of sensitivity analysis in 15 (56%); caveats to conclusions mentioned in 4 (15%).Models of me-too drugs were significantly less likely to report comparisons against relevant alternatives (OR=0.08, p=0.011) or incremental results (OR=0.07, p=0.03). No other significant differences were found. Conclusions Most dossiers submitted to one health plan in 2003 under the AMCP Format contained economic models. Models had low levels of compliance with broadly accepted