The history of Reager & Adler dates back to the year 1979 when Dave Reager and Ted Adler founded the firm both previously working in state government with Ted Adler serving as a Deputy Attorney General and Chief Legal Counsel of the Pennsylvania Department of General Services, and Dave Reager serving as an Assistant Attorney General and Special Counsel to the Deputy Secretary of General Services for Procurement. From the outset, the firm emphasized the practice areas of real estate; estate and business planning; commercial litigation; and construction and administrative law.

The 1980's was a period of change and growth for the firm. Additional attorneys were added, and the firm moved to offices in Harrisburg while maintaining a second office in Camp Hill. Thereafter, the firm consolidated its offices in Camp Hill. In the mid 1990's the firm expanded its practice areas to include family law, land use and zoning and municipal law, and Linus Fenicle joining the firm as a shareholder. In 2001, Chuck Zaleski joined the firm as a shareholder in charge of the firm's land use practice group. Presently, the firm has ten attorneys and six paralegals.

The land use practice group, along with the real estate and construction litigation areas, continue to be the most rapidly growing areas of practice for the firm. The firm expects to continue to pursue opportunities to expand into other areas that complement the current practice areas.

The law firm is rated AV in Martindale-Hubbell's registry of attorneys and is listed in the Martindale-Hubbell bar register of preeminent attorneys in the areas of real estate and construction litigation.