This excerpt taken from the UNH 10-K filed Feb 11, 2009.
Other Intangible Assets
Intangible assets with discrete useful lives are amortized on a straight-line basis over their estimated useful lives unless another method can be reasonably determined. Intangible assets are reviewed for events or changes in circumstances that would indicate an assets carrying value exceeds its estimated fair value in which case an impairment charge would be recorded. The Company considers many factors, including estimated future utility and cash flows associated with the assets, to make this decision. There were no material impairments at December 31, 2008.