In January, UnitedHealth Group’s health services arm Optum announced it would acquire Surgical Care Affiliates (SCA), one of the nation’s largest and most well-respected ambulatory surgery center (ASC) and surgical hospital companies, for $2.3 billion.

With the combination, SCA will become part of the OptumCare platform, which serves consumers through 20,000 affiliated physicians and hundreds of care facilities. At the time of the announcement, SCA was operating 205 surgical facilities, including ASCs and surgical hospitals, in partnership with approximately 3,000 physicians in 30 states.

UnitedHealth Group’s acquisition of SCA may indicate a renewed interest in insurance companies investing in providers after a few years of lighter activity.

As Kaiser Health News reported in mid-2011, four of the five largest health insurers had increased physician holdings in the previous year. Highmark, a not-for-profit insurer, went so far as to acquire an entire health system — West Penn Allegheny Health System — in April 2013. But the surge of insurers acquiring physicians was not sustained, as Modern Healthcare reported in 2015.

However, the trend may now be reversing course. As The New York Times noted in its Optum-SCA coverage, “Insurers are aggressively experimenting with new ways to pay doctors and hospitals to reward them for delivering better care at lower prices. Many doctors are scrambling to join health systems and insurers to avoid being left behind.”

A Fitch Ratings report in January highlights the growing interest in ASCs from insurers and hospitals, citing the SCA acquisition and Tenet’s acquisition of United Surgical Partners International in 2015. As the report notes, “ASCs are desirable targets for health systems and insurers partial to vertical integration strategies because they offer a compelling value proposition as volumes continue to shift to an outpatient setting; all else equal, treatment in an outpatient surgery setting is cheaper than in an acute care hospital due to a more flexible operating model and cheaper capital plant.”

The public markets have generally reacted favorably as well to such merger news. SCA’s stock increased by nearly eight points to $56.65 when the acquisition was announced. Similarly, on that same day, shares of Surgery Partners, another publicly traded ASC management company, increased two points, from $16 to $18 per share, and now sits at about $21 per share.

And many believe this is only the beginning of a revived interest in insurer-provider combinations.