2026 ICD-10-CM Diagnosis Code S27.309DUnspecified injury of lung, unspecified, subsequent encounter

ICD-10-CM Codes›S00–T88›S20-S29›S27

ICD-10-CM S27.309D
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S27.309D is a billable ICD-10-CM diagnosis code for unspecified injury of lung, unspecified, subsequent encounter. The 7th character D marks it as a subsequent encounter code, used during routine care in the healing or recovery phase. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 949 through 950. The code is exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Internal organ injury, subsequent encounter.

Code Identity

ICD-10-CM Code
S27.309D
Billable Status
Yes — Valid for Submission
Code Describes
Unspecified injury of lung, unspecified, subsequent encounter
Short Description
Unspecified injury of lung, unspecified, subs encntr
Parent Code
S27.309
Unspecified injury of lung, unspecified

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS20-S29Injuries to the thorax
CategoryS27Injury of other and unspecified intrathoracic organs
This CodeS27.309DUnspecified injury of lung, unspecified, subsequent encounter

Present on Admission (POA)Billing

S27.309D is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acute lung injury
  • Chylothorax
  • Closed injury of lung
  • Direct acute lung injury
  • Indirect acute lung injury
  • Inhalation injury
  • Inhalation injury due to chemical
  • Injury due to chemical exposure
  • Injury of lung
  • Injury of lung with open wound into thorax
  • Injury of lung without open wound into thorax
  • Injury of pleura, lung or bronchus
  • Injury of thoracic cavity
  • Injury to heart and lung
  • Injury to lung during surgery
  • Injury to respiratory system due to inhalation of particulate matter
  • Lung injury with sepsis
  • Open injury of lung
  • Toxic inhalation injury
  • Traumatic chylothorax
  • Ventilator-associated lung injury

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Injury of other and unspecified intrathoracic organs (S27). Use the following options for the applicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026, published by CMS and the National Center for Health Statistics.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INJ047
Internal organ injury, subsequent encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Acute Lung Injury

    a condition of lung damage that is characterized by bilateral pulmonary infiltrates (pulmonary edema) rich in neutrophils, and in the absence of clinical heart failure. this can represent a spectrum of pulmonary lesions, endothelial and epithelial, due to numerous factors (physical, chemical, or biological).

  • Transfusion-Related Acute Lung Injury

    a rare but serious transfusion-related reaction in which fluid builds up in the lungs unrelated to excessively high infusion rate and/or volume (transfusion-associated circulatory overload). signs of transfusion-related acute lung injury include pulmonary secretions; hypotension; fever; dyspnea; tachypnea; tachycardia; and cyanosis.

  • Chylothorax

    the presence of chyle in the thoracic cavity. (dorland, 27th ed)

  • Traumatic Chylothorax

    accumulation of lymph fluid in the pleural cavity as a result of thoracic trauma.

  • Acquired Chylothorax

    chylothorax that results from malignancies (usually lymphoma), trauma to the thoracic duct, tuberculosis, or sarcoidosis.

  • Chylothorax

    an accumulation of chyle in the pleural cavity.

  • Chylothorax, CTCAE|Chylothorax|Chylothorax|Chylothorax

    a disorder characterized by milky pleural effusion (abnormal collection of fluid) resulting from accumulation of lymph fluid in the pleural cavity.

  • Chylothorax|Chylous Pleural Effusion

    a milky pleural effusion resulting from accumulation of lymph fluid in the pleural cavity. causes include malignancies (usually lymphoma), trauma to the thoracic duct, tuberculosis, sarcoidosis, and congenital causes.

  • Congenital Chylothorax

    chylothorax that is present at birth.

  • Grade 1 Chylothorax, CTCAE|Grade 1 Chylothorax|Grade 1 Chylothorax

    asymptomatic; clinical or diagnostic observations only; intervention not indicated

  • Grade 2 Chylothorax, CTCAE|Grade 2 Chylothorax|Grade 2 Chylothorax

    symptomatic; medical intervention indicated (e.g., fat-restricted diet); thoracentesis or tube drainage indicated

  • Grade 3 Chylothorax, CTCAE|Grade 3 Chylothorax|Grade 3 Chylothorax

    severe symptoms; elective operative intervention indicated

  • Grade 4 Chylothorax, CTCAE|Grade 4 Chylothorax|Grade 4 Chylothorax

    life-threatening respiratory or hemodynamic compromise; intubation or urgent intervention indicated

  • Grade 5 Chylothorax, CTCAE|Grade 5 Chylothorax|Grade 5 Chylothorax

    death

Patient EducationClinical

Chest Injuries and Disorders

The chest is the part of your body between your neck and your abdomen (belly). The medical term for your chest is thorax.

The full article covers:

  • What is the chest?
  • What are chest injuries and disorders?
  • How are chest injuries and disorders diagnosed?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert S27.309D to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
V58.89 Other specfied aftercare
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About S27.309DOverview

Is S27.309D (Unspecified injury of lung, unspecified) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report unspecified injury of lung, unspecified, subsequent encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character D in S27.309D mean?

The final character D marks a subsequent encounter: use it for routine care while the unspecified injury of lung, unspecified is healing, after active treatment has ended.

What MS-DRG does S27.309D group to?

When unspecified injury of lung, unspecified, subsequent encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 949, 950, with relative weights from 0.6277 to 1.1897 depending on complications. Higher weights mean higher Medicare reimbursement.

Is S27.309D exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for unspecified injury of lung, unspecified, subsequent encounter on inpatient claims.

What is the ICD-9 equivalent of S27.309D?

Under the General Equivalence Mappings, unspecified injury of lung, unspecified, subsequent encounter converts to ICD-9-CM V58.89 (other specfied aftercare). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.