via Wall Street Journal

The leaders of the top five health insurers periodically get together to discuss policy issues, Aetna Inc. Chief Executive Mark T. Bertolini told investors in a private meeting earlier this month. The group had a nickname, he joked: the G5. Soon, that could be down to the G3.
The change would come thanks to Mr. Bertolini, who has struck a $34 billion deal for Humana Inc., and Anthem Inc. CEO Joseph Swedish, whose company is seeking to acquire Cigna Corp. for $48 billion. The unprecedented tandem deals could reshape the industry into one topped by three giants, each with more than $100 billion in annual revenue. UnitedHealth Group Inc. would be the third major player and still the largest by revenue.
First, though, Mr. Bertolini and Mr. Swedish will have to run a gantlet of regulatory, political and operational challenges, sharing a joint spotlight that could make each of their jobs harder as they make a case for their combinations.