Malignant neoplasm of nasopharynx (C11) ICD-10-CM
The C11 code range covers malignant neoplasm of nasopharynx with 7 ICD-10-CM diagnosis codes. 6 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Use Additional Code
The “use additional code” indicates that a secondary code could be used to further specify the patient’s condition. This note is not mandatory and is only used if enough information is available to assign an additional code.
Codes in the C11 Range 7 codes · 6 billable
- C11 Malignant neoplasm of nasopharynxNon-billable
- C11.0 Malignant neoplasm of superior wall of nasopharynx
- C11.1 Malignant neoplasm of posterior wall of nasopharynx
- C11.2 Malignant neoplasm of lateral wall of nasopharynx
- C11.3 Malignant neoplasm of anterior wall of nasopharynx
- C11.8 Malignant neoplasm of overlapping sites of nasopharynx
- C11.9 Malignant neoplasm of nasopharynx, unspecified
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the C11 range.
Nasopharyngeal Carcinoma
A carcinoma that originates in the EPITHELIUM of the NASOPHARYNX and includes four subtypes: keratinizing squamous cell, non-keratinizing, basaloid squamous cell, and PAPILLARY ADENOCARCINOMA. It is most prevalent in Southeast Asian populations and is associated with EPSTEIN-BARR VIRUS INFECTIONS. Somatic mutations associated with this cancer have been identified in NPCR, BAP1, UBAP1, ERBB2, ERBB3, MLL2, PIK3CA, KRAS, NRAS, and ARID1A genes.
About the C11 Code Range
The ICD-10 code C11 and its subcodes are used to classify different types of malignant neoplasms of the nasopharynx, which is the upper part of the throat behind the nose. These codes specify the precise location of the cancer within the nasopharynx, from the superior to anterior walls, lateral wall, overlapping sites, or remain unspecified when exact location details are unavailable.
Medical coders use these codes to identify nasopharyngeal cancers accurately, including those referred to by common synonyms like primary squamous cell carcinoma, undifferentiated carcinoma, or lymphoepithelial carcinoma of the nasopharynx. For example, C11.0 is for malignant neoplasm of the superior wall, often called undifferentiated carcinoma of the nasopharynx, while C11.1 covers tumors of the posterior wall, sometimes known as adenoid squamous cell carcinoma. The code C11.9 is used when the cancer’s specific site in the nasopharynx is not documented, encompassing many variants like nasopharyngeal carcinoma or keratinizing squamous cell carcinoma. These distinctions are crucial in clinical documentation for precise diagnosis and treatment planning.
Questions About This Page
How many billable codes are in the C11 range?
Of the 7 codes in this range, 6 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the C11 range classify?
The range classifies malignant neoplasm of nasopharynx. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
