A Walmart sign (Photo: Thinkstock)

Walmart Inc. is in early talks to acquire health insurer Humana Inc., the Wall Street Journal reported, a transaction that would pitch the retailer headlong into a rapidly changing industry whose surging costs and regulatory pressures have led to a series of megadeals.

The details of the discussions aren’t clear, and a deal may fall through, the Journal said, citing unidentified people familiar with the matter. Humana, valued at about $37 billion, would be Walmart’s largest deal on record. Walmart declined to comment to Bloomberg News, while Humana didn’t immediately respond.

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Health care spending accounted for about 18% of the U.S. economy last year, and continues to surge with an aging population, pricey medications and a complex regime of reimbursements and middlemen. Companies have been trying to address some of the market’s inefficiencies by getting bigger: Cigna Corp. is acquiring Express Scripts Holding Co. for $54 billion, and CVS Health Corp. is buying Aetna Inc. for $68 billion.

For Walmart, which operates thousands of pharmacies in its stores, the logic of buying an insurer could be similar to drugstore chain CVS’s plan — gaining more leverage in negotiations with drug companies by taking up a bigger share of purchasing power for pharmaceuticals.

Walmart and Humana already partner on prescription drug plans for individuals in the U.S. Medicare program. The plans offer some prescriptions for as little as $1, as long as customers pick up their drugs at a Walmart or Sam’s Club. Walmart could use the takeover to steer more of Humana’s customers to its stores through its drug coverage arrangements.

Stores can also be a convenient place for individuals to get care, and both CVS and Walmart have clinics in some stores.

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