This standard establishes requirements for assuring quality, safety, performance, and documentation of laboratory-developed tests (LDTs) as per their intended use for the diagnosis, prognosis, monitoring, prevention or treatment of medical conditions. It outlines the general principles and assessment criteria by which an LDT shall be designed, developed, characterized, manufactured, validated (analytically and clinically) and monitored for internal use by medical laboratories. The scope includes regulatory authority approved IVD medical devices that are used in a manner differing from approved labelling or instructions for use for that device (e.g., use of a sample type not included in the intended use, use of instruments or reagents not included in the labelling). While the standard follows a current best practice and state-of-the art approach, it does not provide specific details on how to achieve these requirements within specific disciplines of the medical laboratory nor specific technology platforms. This document does not cover requirements for examination procedures developed by research or academic laboratories developing and using testing systems for non-in-vitro-diagnostic purposes. However, the concepts presented in this document may also be useful for these laboratories. The proposed standard does not apply to the design, development and industrial production of commercially used IVD medical devices. Note International, national, or regional regulations or requirements can also apply to specific topics covered in this document.