(b) Transition of PIID numbering. No later than October 1, 2017, agencies shall comply with paragraph (a) of this section and use the requirements in 4.1602 and 4.1603 for all new solicitations and contract awards. Until an agency’s transition is complete, it shall maintain its 2013 PIID format that is on record with the General Services Administration’s Integrated Award Environment Program Office (which maintains a registry of the agency unique identifier scheme). The 2013 PIID format consisted of alpha characters in the first positions to indicate the agency, followed by alpha-numeric characters; the 2017 format instead has the AAC in the beginning 6 positions.