Deutsche Bank expects average revenue growth of 17.6% in the second quarter (up from 8.0% in the first quarter) due to Medicaid expansions, while average EPS is expected to decline by 13.1% due to a nearly 50% average decline for Medicaid MCOs.

Fidel said Aetna's current share prices may already reflect an earnings per share miss, signaling that a reported EPS of $1.26 -- the current Wall Street consensus -- could drive shares higher. He expects a second quarter earnings miss from Health Net and notes that among Medicaid-exposed names, WellCare may contain the biggest earnings surprise after Molina and Coventry Healthcare pre-announced negative revisions.

The Obamacare M&A chatter shouldn't obscure the fact that health care companies were busy before the decision putting together mega-mergers to position themselves for key earnings opportunities, amid the prospect that profit margins fall throughout the health care sector.

"There is a very basic level of consolidation that is taking place," Marc Cabrera, head of the health care investment banking practice at Morgan Joseph TriArtisan, said in a late June interview that came before the court's ruling.

Cabrera highlighted a consistent drum of mergers among physician practices, hospitals and pharmacy benefits managers (PBMs) -- -- the companies that fill drug prescriptions -- as indicative of the needs for companies in the health care sector to grow their scale in the face of margin pressures.

In June, Walgreen's ( WAG) acquisition of European pharmacy giant Alliance Boots highlighted big changes to the earnings prospects for drug store and PBMs.

Last October, Cigna ( CI) bought HealthSpring ( HS), a health care provider with a big pharmacy unit, in a near doubling of its PBM business.

Cabrera pointed to recent deals like dialysis specialist DaVita's ( DVA) $4.42 billion acquisition of privately held physician practice HealthCare Partners and Humana's acquisition of hospital chain Concentra in 2010 as signs of the health care sector in an M&A mode of scaling operations.

For more on healthcare M&A, see why Obamacare isn't the sole trigger for dealmaking and why M&A among drug stores and pharmacy giants like Express Scripts ( ESRX) could underestimate synergies in the sector.

-- Written by Antoine Gara in New York

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