Riverside Partners has announced it has completed an investment in UnisLink Holdings.

UnisLink, based in Phoenix, Ariz., provides revenue cycle management and population health management services. Founded in 2009, the company serves independent physician groups, accountable care organizations and value-based care groups.

Riverside Partners, based in Boston and founded in 1988, seeks investments in growing middle-market healthcare- and technology-oriented companies. The firm typically invest in companies with revenues between $10 million and $100 million.

Terms of the investments were not disclosed.