Emerald Health Services and Cirrus Medical Staffing Inc. will combine into a single company and will operate under the Emerald Health Services name providing nurse and allied healthcare staffing. The combined company will be led by Mark Siegel, CEO of Emerald since 2013.

Both companies are owned by private equity firm Webster Equity Partners, which acquired Charlotte, North Carolina-based Cirrus in a $37 million deal in 2017 and Los Angeles-based Emerald Health Services last year.

The formal combination began on April 8.

Prior to the firms’ combining, Cirrus Medical ranked No.29 on Staffing Industry Analysts’ list of largest healthcare staffing firms in the US. Emerald ranked No. 42 on the list.