Fortune 500 rank: 21 (Previous rank: 37)
2006 Revenues (millions): $71,542
Headquarters: Minnetonka, MN
Get quote: UNH
A stock options scandal at the health care insurer led to the departure of CEO William McGuire. But the company's $8.1 billion acquisition of PacifiCare, completed in late 2005, helped boost revenues 58% and earnings by 26% last year, moving it up 16 spots on the list.
See more Fortune 500 data for UnitedHealth Group