In 1974, when Allentown-Sacred Heart Hospital opened, a laboratory for clinical and pathology services was established. Over time, the relationship between Allentown Hospital and Sacred Heart was changed, and in the years that ensued, the laboratory of the newly named Lehigh Valley Hospital Center established itself as one of the finest in the region.

In 1985 the clinical laboratories of Lehigh Valley Hospital Center and the Allentown Hospital merged its clinical testing divisions with the exception of transfusion medicine, histology, cytology, and pathology, and the merged entity assumed the name of the parent organization, HealthEast Laboratories. Between 1988 and 1990, the remaining divisions of the laboratory were merged as were the professional pathology corporations providing contracted services to the hospitals.

In April 1992 the lab was renamed Health Network Laboratories (Allentown Hospital and Lehigh Valley Hospital Center were renamed Lehigh Valley Hospital [LVH]).

Operational effectiveness of the laboratory increased, and the laboratory embarked upon organizational, technical, and quality management initiatives. Further improvements in consolidation of testing and state of the art technology (sophisticated instrumentation and robotics) were implemented between 1990 and 1997 including the enlargement of property at 2024 Lehigh Street to house a core laboratory. Rapid Response laboratories were established at LVH locations to provide immediate testing needs on campus.

A reorganization of the laboratory occurred in 1997 and 1998. HNL evolved from a cluster of   hospital cost centers to a free standing, for-profit limited partnership, with LVH being an equity partner. On January 1, 1998, the pathology services formerly contracted by LVH were assigned to HNL and the pathologists became employees of HNL. On July 1, 1998 HNL hired the laboratory employees from LVH, purchased LVH’s laboratory assets, and began providing clinical laboratory services to LVH. Similarly, on October 1, 1998 Muhlenberg Hospital became an equity partner and HNL became the laboratory services provider. In September 2002, Good Shepherd Home and Rehabilitation Hospital became the third limited partner.

In 2019, Health Network Laboratories went through an organizational refresh and became HNL Lab Medicine.