C11.1 Malignant neoplasm of posterior wall of nasopharynx

Billable ICD-10-CM code, FY2026.

Applicable to

• Malignant neoplasm of adenoid
• Malignant neoplasm of pharyngeal tonsil

Applies from C11 Malignant neoplasm of nasopharynx

Use additional code

• code to identify:
• exposure to environmental tobacco smoke (Z77.22)
• exposure to tobacco smoke in the perinatal period (P96.81)
• history of tobacco dependence (Z87.891)
• occupational exposure to environmental tobacco smoke (Z57.31)
• tobacco dependence (F17.-)
• tobacco use (Z72.0)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 21 — Lymphoma and Other Cancers
• CMS-HCC V22: HCC 11 — Colorectal, Bladder, and Other Cancers
• ESRD V24: HCC 11

MS-DRG index

Defines the logic of DRG(s) 011-013 in MDC PRE.

Approximate ICD-9-CM (GEMs)

• 147.1 Malignant neoplasm of posterior wall of nasopharynx

Code annotations containing back-references to C11.1

Back-references to C11.1

• Type 2 Excludes: C09 Malignant neoplasm of tonsil ("malignant neoplasm of pharyngeal tonsil (C11.1)")

Nearby codes

• C11 Malignant neoplasm of nasopharynx
• C11.0 Malignant neoplasm of superior wall of nasopharynx
• C11.1 Malignant neoplasm of posterior wall of nasopharynx (this code)
• 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