As the number of dental insureds and the amount of insured expenditures have increased over the past decade, so has interest in determining insurance effects on dental demand among employer groups and their insureds. Using Pennsylvania Blue Shield (PBS) employer group data representing 50–65% of all PBS insureds, the authors estimate the own-effect of basic insurance rates (diagnostic, preventive, restorative, endodontic, extraction services) and the cross-effects of riders A (crowns and oral surgery), B (prosthodontics), C (periodontics), and D (orthodontics) insurance rates on annual basic expenditures for 1975–1979. Results indicate a consistently positive relationship between basic insurance rates and expenditures. Orthodontic insurance rates have positive cross-effects on basic expenditures, suggesting basic–orthodontic complementarities. Although not statistically significant, potential substitution relationships may exist between basic and oral surgery, prosthodontic, and periodontic services. The implications of these findings for plan design and public oral health are discussed.