Recent initiatives of the American Board of Medical Specialties (ABMS) in the area of maintenance of certification (MOC) have been reflective of the response of the medical community to address public concerns regarding quality of care, medical error reduction, and patient safety. In March 2000, the 24 member boards of the ABMS representing all medical subspecialties in the USA agreed to initiate specialty-specific maintenance of certification (MOC) programs. The American Board of Radiology (ABR) MOC program for diagnostic radiology, radiation oncology, and radiologic physics has been developed, approved by the ABMS, and initiated with full implementation for all three disciplines beginning in 2007. The overriding objective of MOC is to improve the quality of health care through diplomate-initiated learning and quality improvement. The four component parts to the MOC process are: Part I: Professional standing, Part II: Evidence of life long learning and periodic self-assessment, Part III: Cognitive expertise, and Part IV: Evaluation of performance in practice (with the latter being the focus of this paper). The key components of Part IV require a physicist-based response to demonstrate commitment to practice quality improvement (PQI) and progress in continuing individual competence in practice. Diplomates of radiologic physics must select a project to be completed over the ten-year cycle that potentially can improve the quality of the diplomate's individual or systems practice and enhance the quality of care. Five categories have been created from which an individual radiologic physics diplomate can select one required PQI project: (1) Safety for patients, employees, and the public, (2) accuracy of analyses and calculations, (3) report turnaround time and communication issues, (4) practice guidelines and technical standards, and (5) surveys (including peer review of self-assessment reports). Each diplomate may select a project appropriate for an individual, participate in a project within a clinical department, participate in a peer review of a self-assessment report, or choose a qualified national project sponsored by a society. Once a project has been selected, the steps are: (1) Collect baseline data relevant to the chosen project, (2) review and analyze the data, (3) create and implement an improvement plan, (4) remeasure and track, and (5) report participation to the ABR, using the template provided by the ABR. These steps begin in Year 2, following training in Year 1. Specific examples of individual PQI projects for each of the three disciplines of radiologic physics are provided. Now, through the MOC programs, the relationship between the radiologic physicist and the ABR will be continuous through the diplomate's professional career. The ABR is committed to providing an effective infrastructure that will promote and assist the process of continuing professional development including the enhancement of practice quality improvement for radiologic physicists.