ICD-10-CM Diagnosis Code (2025)
Official Description for C31
Malignant neoplasm of accessory sinuses
Coding Notes & Guidelines for C31
Inclusion Terms
Malignant neoplasm of antrum (Highmore) (maxillary)
Child Codes (More Specific Codes for C31):
C31.0 - Malignant neoplasm of maxillary sinus
C31.1 - Malignant neoplasm of ethmoidal sinus
C31.2 - Malignant neoplasm of frontal sinus
C31.3 - Malignant neoplasm of sphenoid sinus
C31.8 - Malignant neoplasm of overlapping sites of accessory sinuses
C31.9 - Malignant neoplasm of accessory sinus, unspecified
About ICD-10-CM Code C31 (Malignant neoplasm of accessory sinuses)
ICD-10-CM code C31 is a billable or specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes. The 2025 edition of ICD-10-CM C31 became effective on October 1, 2024.
This page provides detailed information about C31 - Malignant neoplasm of accessory sinuses. It includes common terminology, coding guidelines such as "Includes," "Excludes1," and "Excludes2" notes, and information on required 7th characters. Utilizing this information correctly is essential for accurate medical coding and claims submission for conditions like Malignant neoplasm of accessory sinuses.