Professional Development Units (PDUs) is the measuring unit used by PMI to quantify approved learning and professional service activities. PMPs must complete and submit sixty PDUs to PMI in order to re-certify their PMP status. These activities must be related to project management topics that are substantially consistent with the knowledge areas and processes as outlined by the Guide to the PMBOK® and involve appropriate expert resources. Typically, one PDU is earned for every one hour spent in a planned, structured learning experience or activity. The latest and most detailed information can be found in the CCR Program Handbook and the Continuing Certification Requirements FAQs.