Investors seem unfazed by the Democratic presidential candidates’ debate around the topic of “Medicare for All.” Mergers and acquisitions in the Managed Care sector are flowing quite well this year.

Halfway through September, 20 deals have been announced, putting this sector on track to equal or possibly exceed the 25 deals announced in 2018. Over the last decade, annual deal volume in this sector has averaged 20 deals per year.

The peak was hit in 2015 with 43 deals, not including the terminated mega-deals between Aetna and Humana (NYSE: HUM) for $37 billion and Anthem (NYSE: ANTM) and Cigna (NYSE: CI) for $54 billion. In June of that year the U.S. Supreme Court ruled that the federal subsidies paid to low-income individuals and families who registered for health insurance through were constitutional. The ruling opened the door to a flood (relatively speaking) of managed care deals, many of them targeting companies with hefty Medicare, Medicare Advantage and Medicaid memberships.

The only mega-deal to receive the FTC’s blessing was Centene Corporation‘s (NYSE: CNC) $6.8 billion acquisition of smaller rival Health Net (NYSE: HNT). Centene came back in 2019 with an even larger acquisition, paying approximately $17.4 billion for WellCare Health Plans (NYSE: WCG), announced in March 2019. That followed the January 2019 announcement the company would buy QualChoice Holdings from not-for-profit Catholic Health Initiatives (now called CommonSpirit Health after CHI finalized its merger with Dignity Health early in 2019).

Not-for-profits are on the move. West Virginia Health, the largest not-for-profit health system in that state, merged with The Health Plan, an HMO with 20,000 members, based in Wheeling. In August, Boston-based Tufts Health Plan (1.16 million members) and Harvard Pilgrim Health (1.2 million) announced their merger.

Private equity firms are active in this space, as well. Centerbridge Partners made a big bet on GoHealth, LLC in August. Norwest Equity Partners agreed to take $1.4 billion to part with the direct-to-consumer platform specializing in Medicare Advantage products. LLR Partners paid an undisclosed price for CareATC Inc., an employer-sponsored heatlhcare marketplace and clinic network with more than 250,000 patients in 35 states.

Consolidation is taking place in the niche markets. Two California-based providers got together in January. Orange-based Western Dental Services a subsidiary of Premier Dental Holdings, acquired Watsonville-based EyeMax Vision Plan in January. Premier Dental is a portfolio company of New Mountain Capital, which acquired Western Dental in 2012. And Boston-based DentaQuest took on The Dental Care Plus Group in Ohio, with 380,000 members.