2027 ICD-10-CM Diagnosis Code C39.9Malignant neoplasm of lower respiratory tract, part unspecified
ICD-10-CM Codes›C00–D49›C30-C39›C39
- Billable — Valid for Submission
- Risk Adjusts — HCC 21
- Chronic Condition
C39.9 is a billable ICD-10-CM diagnosis code for malignant neoplasm of lower respiratory tract, part unspecified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 180 through 182. Coders also document this condition as malignant neoplasm of lower respiratory tract. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Respiratory cancers.
For Medicare Advantage risk adjustment, C39.9 maps to CMS-HCC Category 21 (Lymphoma and Other Cancers) under the V28 model, adding a risk factor of about 0.671 for a community, non-dual, aged beneficiary in payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
C39.9 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.
Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Malignant neoplasm of lower respiratory tract
- Malignant neoplasm of respiratory system
- Primary malignant neoplasm of respiratory tract
- Primary rhabdomyosarcoma of respiratory organ
- Primary squamous cell carcinoma of respiratory system
- Primary synovial sarcoma
- Primary synovial sarcoma of respiratory organ
- Synovial sarcoma
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to C39.9: its own notes plus those printed at C39, block C30-C39, and Chapter 2. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- malignant neoplasm of middle ear
Applicable To
Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.
- Malignant neoplasm of respiratory tract NOS
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
- mesothelioma (C45.-)
Use Additional Code
Add a second code, after this one, to fully describe the condition.
Notes
General instructions on how these codes are used.
- Functional activity
- All neoplasms are classified in this chapter, whether they are functionally active or not. An additional code from Chapter 4 may be used, to identify functional activity associated with any neoplasm.
- Morphology [Histology]
- Chapter 2 classifies neoplasms primarily by site (topography), with broad groupings for behavior, malignant, in situ, benign, etc. The Table of Neoplasms should be used to identify the correct topography code. In a few cases, such as for malignant melanoma and certain neuroendocrine tumors, the morphology (histologic type) is included in the category and codes.
- Primary malignant neoplasms overlapping site boundaries
- A primary malignant neoplasm that overlaps two or more contiguous (next to each other) sites should be classified to the subcategory/code .8 ('overlapping lesion'), unless the combination is specifically indexed elsewhere. For multiple neoplasms of the same site that are not contiguous, such as tumors in different quadrants of the same breast, codes for each site should be assigned.
- Malignant neoplasm of ectopic tissue
- Malignant neoplasms of ectopic tissue are to be coded to the site mentioned, e.g., ectopic pancreatic malignant neoplasms are coded to pancreas, unspecified (C25.9).
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name C39.9, its category, or a range that includes it.
Applicable To 1
These notes mention C39.9.
- Z80.2 Family history of malignant neoplasm of other respiratory and intrathoracic organs
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Table of NeoplasmsClinical
Patient EducationClinical
Lung Cancer
Lung cancer is cancer that forms in tissues of the lung, usually in the cells that line the air passages. It is the leading cause of cancer death in both men and women.
The full article covers:
- What is lung cancer?
- Who is more likely to develop lung cancer?
- What are the symptoms of lung cancer?
- How is lung cancer diagnosed?
- What are the treatments for lung cancer?
- Can lung cancer be prevented?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert C39.9 to ICD-9-CMHistory
Code HistoryHistory
Questions About C39.9Overview
What is the ICD-10 code for malignant neoplasm of lower respiratory tract, part unspecified?
The ICD-10-CM code for malignant neoplasm of lower respiratory tract, part unspecified is C39.9 (sometimes written as C399). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is C39.9 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report malignant neoplasm of lower respiratory tract, part unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does C39.9 group to?
When malignant neoplasm of lower respiratory tract, part unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 181, 180, 182, with relative weights from 0.7436 to 1.7800 depending on complications. Higher weights mean higher Medicare reimbursement.
Can C39.9 be reported with C76.1?
Not as a rule. The Excludes1 note at C39, which applies to C39.9, lists "intrathoracic malignant neoplasm NOS (C76.1)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
Does C39.9 need an additional code?
When the condition applies, yes. The Use Additional Code note at C39, which applies to C39.9, reads: 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 listed in the Instructional Notes section. The additional code is reported after C39.9.
What HCC is C39.9?
C39.9 (malignant neoplasm of lower respiratory tract, part unspecified) maps to CMS-HCC Category 21 (Lymphoma and Other Cancers), commonly written as HCC 21, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 11 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 22.
Does C39.9 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, C39.9 adds a risk adjustment factor of about 0.671 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.493 to 0.739 depending on the payment segment). A more severe related category (HCC 17, HCC 18, HCC 19, and HCC 20) supersedes it when both are reported. See the full factor table on the HCC 21 category page.
