This archived document is no longer being reviewed through the CLSI Consensus Document Development Process. However, this document is technically valid as of March 2017. Because of its value to the laboratory community, it is being retained in CLSI's library.Clinical and Laboratory Standards Institute document MM19-A--Establishing Molecular Testing in Clinical Laboratory Environments; Approved Guideline provides a framework for decision making and implementation of clinical molecular diagnostics, and is intended for those in established clinical laboratories that are implementing a molecular program for the first time. When implementing any diagnostic test for patient care, many elements should be addressed before the test is brought online. This document focuses on the path of workflow, including laboratory safety and the quality management system, with emphasis on considerations for molecular diagnostics. An organized approach to strategic planning with SWOT (strengths, weaknesses, opportunities, and threats) is presented. Relevant regulatory requirements and the implementation plan are discussed in detail. Importantly, separate sections are devoted to each of the following subspecialty areas: heritable diseases, oncology and malignant hematology, pharmacogenomics, and infectious diseases. Each of these sections addresses special considerations for molecular testing for each subspecialty