St. Louis-based Ascension Health and Renton, Washington-based Providence St. Joseph Health are discussing a merger, according to the Wall Street Journal, which would create a massive nonprofit health system of 191 hospitals in 27 states.

With a combined revenue of $44.8 billion, it would dethrone for-profit operator HCA’s 177 hospitals and $41.5 billion in revenue to become the largest hospital chain in the U.S. Ascension on its own is already the largest integrated health system by number of facilities and was set to expand through its acquisition of Chicago-based Presence Health, the largest Catholic health system in Illinois.

According to WSJ, the two have been in talks for months, but no deal is certain. Neither system commented on the rumors. The Seattle Times quoted another source familiar with the situation saying the two systems have “grown closer in recent weeks” with a development of an agreement that would allow the two organizations to share anonymized patient data.

The Seattle Times also reported the combined entity may be headquartered out of Chicago. This would echo the same move by the merging Dignity Health and Catholic Health Initiatives despite neither system being based in Chicago.

While regulatory approval would be needed for the merger to go forward, the two systems are largely based out of different markets, with Ascension’s locations centered around the South and Midwest and Providence largely based in the West. They do have some overlap in Texas and Washington.

The merger is just one rumored deal in a flurry of M&A activity announced so far this month. Other deals have included the $69 billion CVS-Aetna merger, the Dignity-CHI merger with $28 billion in combined revenue and the combination of Advocate Health Care and Aurora Health Care into a 27-hospital, $11 billion system.