[3] Quality Systems, Inc. (QSI) was formed by Sheldon Razin in 1973[4] in Corona, California, as a dental software company.

[7] In May 1997, QSI purchased Micromed, which provided front- and back office practice management software.

In 2008, NextGen Healthcare then acquired HSI[9] of St. Louis, Missouri, and Practice Management Partners of Hunt Valley, Maryland, to expand its billing services and revenue cycle consulting division.

[15] On October 30, 2015, Quality Systems announced an agreement to acquire HealthFusion for $165 million-plus potential additional contingent consideration of up to $25 million.

Based in San Diego, Calif., HealthFusion was a privately held developer of web-based software for physicians, hospitals and medical billing services.