PDH carryover refers to the practice of a professional engineer earning PDH credits in one renewal cycle and carrying the credits forward to be applied in the next renewal cycle. Most states allow between 50% to 100% of the required # of PDH to be carried forward, although no state allows more than 15 PDH of carryover.

The following states do not allow any PDH carryover: District of Columbia, Florida, Illinois, Michigan, Vermont, and Virginia