A Statement of Creditable Service (SOCS) request must be sent to PPC (ADV) by the SPO completing the accession whenever a member with prior service is accessed into the Coast Guard or Coast Guard Reserve. Prior service data is entered by the SPO as part of the accession process. The SPO will file a copy of the SOCS request in the member's PDR, section 1, to serve as supporting documentation for crediting the member with prior service time for pay entry base date and active duty base date purposes. If the SPO completing the accession did not submit a SOCS request, the SPO at the member's first PDS must complete the request upon receipt of the PDR from the accession point. Page 5-C-5 of the Personnel and Pay Procedures Manual, PPCINST M1000.2 (series) provides the procedure and lists other times when a SOCS request must be submitted.
For PPC (ADV) to generate an accurate service statement all prior service documentation should be scanned and emailed to PPC Customer Care. This includes all contracts and all discharge documents including DD-214's and NGB 22 and 23's for National Guard members. (NGB Documents are the National Guard's version of the DD-214 and enlistment contracts).
See http://www.uscg.mil/ppc/adv.asp for more information.