Seeing claims returned with reason code 31313? Check the Release of Indicator (RI) field (Form Locator 52) for invalid values, HHH Medicare Administrative Contractor CGS suggests. Depending on the type of claim submission you use (5010A, DDE, hard copy, or 4010A1), invalid values can include "Y," "I," or blank. Valid values can include "A", "I", "M", "N", "O" or "Y," CGS says on its website.