Unless otherwise noted, codes are stated in the minimum specificity required. For example, if a three-digit code is listed, it is valid as a three-, four- or five-digit code. If a table lists ICD-9-CM Diagnosis code 401, the codes 401.0, 401.1 and 401.9 are acceptable for P4P reporting. When required, a code will be specified with an x, which represents a valid digit that must be used for reporting. For example, ICD-9-CM diagnosis code 640.x1 indicates that any valid fourth digit can be used if the fifth digit is 1.