The inter-relationship between private health insurance cover and hospital utilisation is complex. The current policy approach in Australia appears to rely on relatively simple models of the relationships between health insurance coverage, and public and private hospital use. There is considerable evidence of unexplained heterogeneity among the privately insured population. Heterogeneity of preferences is likely to be important not just in determining the uptake of private health insurance, but also the impact of changes in private health insurance on the use of private treatment. A number of studies have used attitudinal variables to model heterogeneity of preferences in other contexts. This study uses the 2001 ABS National Health Survey to identify ‘types’ among the insured population using their stated reasons for purchasing private health insurance. The authors, D. Fiebig, E. Savage, and R. Viney find that insurance type is significantly associated with hospital utilisation, particularly the probability of being admitted as a public or private patient. We also find that the government’s insurance incentives were more attractive to particular types of the insured population. This has implications for the effectiveness of the insurance incentives and for the design of policies that aim to reduce pressure on the public hospital system.