Both Anthem Inc. and Aetna Inc. Saturday moved to acquire smaller rivals, actions that could reduce the big five health insurance companies to just three and raise antitrust concerns. Anthem, based in Indianapolis, said it has upped the ante in its bid to acquire Cigna Corporation. A short time later, news emerged Aetna is making a bid for Humana Inc. The moves are part of an effort by the nation's largest publicly traded health insurance providers to consolidate, something that physicians warn could lead to higher premiums and lower payouts to doctors and hospitals. 

“This combination is the absolute best strategy for both organizations to maximize the potential and lead the transformation of the healthcare industry,” Joseph Swedish, president and chief executive officer of Anthem, said in a statement Saturday. “Together our companies would ... deliver innovative, quality solutions to all of our stakeholders.”

Anthem said it increased its offer to $184 per share in cash and stock for Cigna, based in Bloomfield, Connecticut, in a $54 billion deal, though it warned Cigna CEO David Cordani might not retain his position. Anthem said it is confident the deal would receive regulatory approval. Anthem and Cigna are two of the so-called Big Five providers of health insurance plans. The other three are UnitedHealth Group Inc., Aetna and Humana. Aetna has been named as a possible buyer of Humana or Cigna in the past, and UnitedHealth, the country’s largest health insurer, has been in talks to acquire Aetna. The Wall Street Journal reported Saturday that Aetna, based in Hartford, Connecticut, has made a bid for Humana, which is headquartered in Louisville, Kentucky. If Anthem and Aetna succeed, the big five U.S. health insurance providers will become the big three.

This is a problem, physicians warn. 

“Everybody should have serious concerns about that,” Dennis Olmstead, chief strategy officer and medical economist at the Pennsylvania Medical Society, the state physicians’ lobbying group, told the Pittsburgh Post-Gazette. “Competition is usually good. ... That’s why we have federal antitrust laws.”

The Federal Trade Commission and the U.S. Justice Department could scrutinize any deals that reduce the number of big health insurers from five to three. Earlier this month, the American Academy of Family Physicians sent a letter to the FTC Chairwoman Edith Ramirez urging her agency to be vigilant of the potential harm of industry consolidation.

“Recent actions by the insurance industry, with respect to the narrowing of physician and hospital networks, would only be exacerbated if a single insurer held greater influence over any potential market,” AAFP Board Chair Reid Blackwelder, said in the letter.