This excerpt taken from the UNH 10-K filed Feb 21, 2008.
If we fail to effectively estimate and manage our health care costs, the profitability of our risk-based products could decline and could materially adversely affect our future financial results.
Under our risk-based product arrangements, we assume the risk of both medical and administrative costs for our customers in return for monthly premiums. Premium revenues from risk-based products comprise approximately 90% of our total consolidated revenues. We generally use approximately 80% to 85% of our premium revenues to pay the costs of health care services delivered to these customers. The profitability of our risk-based products depends in large part on our ability to predict, price for, and effectively manage health care costs. Total health care costs are affected by the number of individual services rendered and the cost of each service. Our premium revenue on commercial policies is typically fixed for a 12-month period and is generally priced one to four months before the contract commences. Our revenue on Medicare policies is based on bids submitted in June the year before the contract year. We base the premiums we charge and our Medicare bids on our estimate of future health care costs over the fixed contract period; however, medical cost inflation, regulations and other factors may cause actual costs to exceed what was estimated and reflected in premiums or bids. These factors may include increased use of services, increased cost of individual services, catastrophes, epidemics, the introduction of new or costly treatments and technology, new mandated benefits or other regulatory changes, insured population characteristics and seasonal changes in the level of health care use. As a measure of the impact of medical cost on our financial results, relatively small differences between predicted and actual medical costs or utilization rates as a percentage of revenues can result in significant changes in our financial results. For example, if medical costs increased by 1% without a proportional change in related revenues for commercial insured products, our annual net earnings for 2007 would have been reduced by approximately $190 million. In addition, the financial results we report for any particular period include estimates of costs that have been incurred for which claims are still outstanding. If these estimates prove too low, they will have a negative impact on our future results.