C06.80Malignant neoplasm of overlapping sites of unspecified parts of mouth

C06.80 is the ICD-10-CM diagnosis code for malignant neoplasm of overlapping sites of unspecified parts of mouth. It belongs to category C06 (malignant neoplasm of other and unspecified parts of mouth), block C00-C14 (malignant neoplasms of lip, oral cavity and pharynx) and chapter 2 (neoplasms). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within C06.8, choose C06.80 (unspecified parts of mouth) only when documentation doesn't support a more specific option: other parts of mouth (C06.89).

Use an additional code to identify: alcohol abuse and dependence (F10.-), history of tobacco dependence (Z87.891), tobacco dependence (F17.-) and tobacco use (Z72.0).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 011 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with MCC, relative weight 5.6154), DRG 012 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with CC, relative weight 4.381), DRG 013 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy without CC/MCC, relative weight 2.7307), DRG 146 (Ear, Nose, Mouth and Throat Malignancy with MCC, relative weight 2.1329), DRG 147 (Ear, Nose, Mouth and Throat Malignancy with CC, relative weight 1.3055) and DRG 148 (Ear, Nose, Mouth and Throat Malignancy without CC/MCC, relative weight 0.8008), in Pre-MDC and MDC 03 (Diseases and Disorders of the Ear, Nose, Mouth and Throat), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 145.8 (malignant neoplasm of other specified parts of mouth).