Medicare contractors are returning claims for correction or resubmission to mental health professionals who fail to indicate in line item 21 of the 1500 claim form whether ICD-9 or ICD-10 codes are used.
For services that were provided prior to October 1, 2015, ICD-9 codes should be used even if the claim is filed after that date; for services on or after October 1, 2015, ICD-10 codes should be used. ICD-9 codes are indicated by using a 9 in item #21; ICD-10 codes are noted with a 0.
DSM-5 lists both the ICD-9 and the ICD-10 codes for each diagnosis. The ICD-9 codes are in black ink and the ICD-10 codes are to the right of them in gray ink.
For information about how to implement ICD-10 codes using DSM-5, see Using DSM-5 in the Transition to ICD-10.