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ICD-10-CM 2027 diagnosis code

C34.2Malignant neoplasm of middle lobe, bronchus or lung

✓ Billable / specificCC — complication/comorbidity

C34.2 is a valid, billable ICD-10-CM code for malignant neoplasm of middle lobe, bronchus or lung. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About C34.2

C34.2 is the ICD-10-CM diagnosis code for malignant neoplasm of middle lobe, bronchus or lung. It belongs to category C34 (malignant neoplasm of bronchus and lung), block C30-C39 (malignant neoplasms of respiratory and intrathoracic organs) 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 C34 (malignant neoplasm of bronchus and lung), C34.2 is specifically for malignant neoplasm of middle lobe, bronchus or lung. Related codes cover main bronchus (C34.0), upper lobe, bronchus or lung (C34.1), lower lobe, bronchus or lung (C34.3), overlapping sites of bronchus and lung (C34.8) and unspecified part of bronchus or lung (C34.9).

Use an additional 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.-) and 1 more.

As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 180 (Respiratory Neoplasms with MCC, relative weight 1.7806), DRG 181 (Respiratory Neoplasms with CC, relative weight 1.0936) and DRG 182 (Respiratory Neoplasms without CC/MCC, relative weight 0.7439), in MDC 04 (Diseases and Disorders of the Respiratory System), 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 162.4 (malignant neoplasm of middle lobe, bronchus or lung).

Notes that apply from higher levels

Instructions written at a parent level also apply to C34.2.

› From C34 Malignant neoplasm of bronchus and lung
Excludes1
  • 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)

Broader instructions also apply from C30-C39 Malignant neoplasms of respiratory and intrathoracic organs and Chapter 2: Neoplasms.

Table of Drugs & Neoplasms entries

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

ICD-9-CM equivalent

Converter →
  • 162.4Malignant neoplasm of middle lobe, bronchus or lungexact

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about C34.2

Is C34.2 billable?

Yes. C34.2 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can C34.2 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict C34.2 as a principal diagnosis.

Is C34.2 a CC or MCC?

C34.2 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.

What DRG does C34.2 group to?

C34.2 is used in the MS-DRG v44.0 logic for MS-DRG 180 (Respiratory Neoplasms with MCC), MS-DRG 181 (Respiratory Neoplasms with CC) and MS-DRG 182 (Respiratory Neoplasms without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

What is the ICD-9 code for C34.2?

The CMS General Equivalence Mappings map C34.2 to ICD-9-CM 162.4.