Is C31 a billable ICD-10-CM code?

No. C31 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does C31 sit in the tabular list?

Neoplasms (C00-D49), in the block Malignant neoplasms of respiratory and intrathoracic organs (C30-C39).

C31

C31 — Malignant neoplasm of accessory sinuses

Non-billable headerICD-10-CM

C31 is a non-billable header ICD-10-CM code for malignant neoplasm of accessory sinuses. It cannot be billed on its own: choose one of the more specific child codes below.

Risk adjustment

C31 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Code to one of these instead C31

6 child codes. Green means billable.

C31.0Malignant neoplasm of maxillary sinus
C31.1Malignant neoplasm of ethmoidal sinus
C31.2Malignant neoplasm of frontal sinus
C31.3Malignant neoplasm of sphenoid sinus
C31.8Malignant neoplasm of overlapping sites of accessory sinuses
C31.9Malignant neoplasm of accessory sinus, unspecified

Questions about C31

Is C31 a billable ICD-10-CM code?: No. C31 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does C31 sit in the tabular list?: Neoplasms (C00-D49), in the block Malignant neoplasms of respiratory and intrathoracic organs (C30-C39).