Until recently there has been no unifying consensus concerning the stages and steps necessary to establish a test method and for the end-user laboratory to then implement the test method. CLSI has recently completed EP19-A - A Framework for Utilizing CLSI Guidelines to Evaluate Clinical LAboratory Assays: Approved Guideline. This session will highlight important aspects of the EP19-A document with emphasis on its utility for creating laboratory-developed tests (LDTs). It will explain the relevance of FDA's Quality System Regulation for LDTs and introduce CLSI's new guide for applying OSR regulations for LDTs. Alternative approaches to QC design, evaluation, and implementation will be discussed with an emphasis on individualized QC plants (IQCPs).