C34.90 Malignant neoplasm of unspecified part of unspecified bronchus or lung

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Applicable to

• Lung cancer NOS

Applies from C34 Malignant neoplasm of bronchus and lung

Excludes1 (never code together)

• Kaposi's sarcoma of lung (C46.5-)
• malignant carcinoid tumor of the bronchus and lung (C7A.090)

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 20 — Lung and Other Severe Cancers
• CMS-HCC V22: HCC 9 — Lung and Other Severe Cancers
• RxHCC V08: HCC 20 — Lung, Kidney, and Other Cancers; Secondary Cancer of Lymph Nodes and Other Sites
• ESRD V24: HCC 9

MS-DRG index

Defines the logic of DRG(s) 180-182 in MDC 04.

Approximate ICD-9-CM (GEMs)

• 162.9 Malignant neoplasm of bronchus and lung, unspecified (approximate)

Code annotations containing back-references to C34.90

Back-references to C34

• Code First: J93.12 Secondary spontaneous pneumothorax ("malignant neoplasm of bronchus and lung (C34.-)")

Diagnosis Index entries for C34.90

• Cancer › lung
• Carcinoma (malignant) › large cell › small cell › unspecified site
• Carcinoma (malignant) › oat cell › unspecified site
• Carcinoma (malignant) › small cell › fusiform cell › unspecified site
• Carcinoma (malignant) › small cell › intermediate cell › unspecified site
• Carcinoma (malignant) › small cell › large cell › unspecified site

Nearby codes

• C34.8 Malignant neoplasm of overlapping sites of bronchus and lung
• C34.80 Malignant neoplasm of overlapping sites of unspecified bronchus and lung
• C34.81 Malignant neoplasm of overlapping sites of right bronchus and lung
• C34.82 Malignant neoplasm of overlapping sites of left bronchus and lung
• C34.9 Malignant neoplasm of unspecified part of bronchus or lung
• C34.90 Malignant neoplasm of unspecified part of unspecified bronchus or lung (this code)
• C34.91 Malignant neoplasm of unspecified part of right bronchus or lung
• C34.92 Malignant neoplasm of unspecified part of left bronchus or lung