Aquiline Capital Partners, a private investment firm based in New York and London, agreed to invest in National Medical Billing Services, a healthcare revenue cycle management company. Financial terms were not disclosed. "The team at National Medical has built an impressive business that serves as a trusted advisor helping their clients navigate the increasing complexity of the healthcare system. We are excited to partner with National Medical, where we can employ our experience at the intersection of healthcare and insurance to help the Company continue innovating to further enhance and expand its business and operations," Jeff Greenberg, Aquiline Capital Partners Chairman and CEO.