In SAE J1939, the acronym PGN stands for Parameter Group Number and represents the identifier of a J1939 message. Every J1939 message has a unique PGN assigned to it by the SAE committee when the message is defined.

A PGN is 18-bits wide and is made up of the following fields: Extended Data Page, Data Page, PDU Format, PDU Specific. Depending on the value of the PDU Format field, a message is either destination specific, meaning it is for a specific CA, or global, meaning it is for all CAs. The PGN identifier is encoded to allow for a maximum of 8,672 unique PGNs.