2026 ICD-10-CM Diagnosis Code Q33.3Agenesis of lung

ICD-10-CM Codes›Q00-Q99›Q30-Q34›Q33

ICD-10-CM Q33.3
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Q33.3 is a billable ICD-10-CM diagnosis code for agenesis of lung. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 205 through 206. The code is exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Respiratory congenital malformations.

Code Identity

ICD-10-CM Code
Q33.3
Billable Status
Yes — Valid for Submission
Code Describes
Agenesis of lung
Short Description
Agenesis of lung
Same as the full description in the CMS dataset.
Parent Code
Q33
Congenital malformations of lung

Code Classification

ChapterQ00-Q99Congenital malformations, deformations and chromosomal abnormalities
SectionQ30-Q34Congenital malformations of the respiratory system
CategoryQ33Congenital malformations of lung
This CodeQ33.3Agenesis of lung

Present on Admission (POA)Billing

Q33.3 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.

  • Absence of lung
  • Agenesis of bilateral lungs
  • Agenesis of left lung
  • Agenesis of lobe of lung
  • Agenesis of lung
  • Agenesis of right lung
  • Congenital absence of lobe of lung
  • Congenital absence of lung
  • Congenital absence of lung fissures
  • Congenital aplasia of lung
  • Functionally congenital single lung
  • Lung agenesis with heart defect and thumb anomaly syndrome
  • Unilobar lung

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Congenital absence of lung (lobe)

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Absence(of) (organ or part) (complete or partial)
      • lung (fissure) (lobe) (bilateral) (unilateral) (congenital)
    • Agenesis
      • lung (fissure) (lobe) (bilateral) (unilateral)
    • Aplasia
      • lung, congenital (bilateral) (unilateral)

Clinical ClassificationClinical

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

CCSR MAL007
Respiratory congenital malformations
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Birth Defects

A birth defect is a problem that happens while a baby is developing in the mother's body. Most birth defects happen during the first 3 months of pregnancy. One out of every 33 babies in the United States is born with a birth defect.

The full article covers:

  • What are birth defects?
  • What causes birth defects?
  • Who is at risk of having a baby with birth defects?
  • How are birth defects diagnosed?
  • What are the treatments for birth defects?
  • Can birth defects be prevented?

Read the full article at MedlinePlus

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

Convert Q33.3 to ICD-9-CMHistory

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

ICD-9-CM
748.5 Agenesis of lung
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 Q33.3Overview

Is Q33.3 (Congenital malformations of lung) a billable code?

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

What MS-DRG does Q33.3 group to?

When agenesis of lung is the principal diagnosis on an inpatient stay, it groups to MS-DRG 205, 206, with relative weights from 0.9411 to 1.8310 depending on complications. Higher weights mean higher Medicare reimbursement.

Is Q33.3 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 agenesis of lung on inpatient claims.

What is the ICD-9 equivalent of Q33.3?

Under the General Equivalence Mappings, agenesis of lung converts to ICD-9-CM 748.5 (agenesis of lung). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.