2026 ICD-10-CM Diagnosis Code Q40.0Congenital hypertrophic pyloric stenosis

ICD-10-CM Codes›Q00-Q99›Q38-Q45›Q40

ICD-10-CM Q40.0
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Q40.0 is a billable ICD-10-CM diagnosis code for congenital hypertrophic pyloric stenosis. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 393 through 395. The code is exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Digestive congenital anomalies.

Code Identity

ICD-10-CM Code
Q40.0
Billable Status
Yes — Valid for Submission
Code Describes
Congenital hypertrophic pyloric stenosis
Short Description
Congenital hypertrophic pyloric stenosis
Same as the full description in the CMS dataset.
Parent Code
Q40
Other congenital malformations of upper alimentary tract

Code Classification

ChapterQ00-Q99Congenital malformations, deformations and chromosomal abnormalities
SectionQ38-Q45Other congenital malformations of the digestive system
CategoryQ40Other congenital malformations of upper alimentary tract
This CodeQ40.0Congenital hypertrophic pyloric stenosis

Present on Admission (POA)Billing

Q40.0 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.

  • Congenital constriction of pylorus
  • Congenital hypertrophic pyloric stenosis
  • Congenital hypertrophy of pylorus
  • Congenital junctional epidermolysis bullosa
  • Congenital junctional epidermolysis bullosa-pyloric atresia syndrome
  • Congenital pyloric spasm
  • Congenital pyloric stenosis
  • Congenital stenosis of stomach
  • Gastric atresia
  • Generalized junctional epidermolysis bullosa
  • Intellectual disability, hypotonia, brachycephaly, pyloric stenosis, cryptorchidism syndrome
  • Pyloric antral stenosis
  • Pyloric atresia
  • Pyloric obstruction
  • Pyloric stenosis
  • Pylorospasm

Tabular List NotesGuidance

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

Inclusion Terms

  • Congenital or infantile constriction
  • Congenital or infantile hypertrophy
  • Congenital or infantile spasm
  • Congenital or infantile stenosis
  • Congenital or infantile stricture

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.

    • Achalasia(cardia) (esophagus)
      • pylorus
    • Constriction
      • pylorus (adult hypertrophic)
        • congenital or infantile
    • Constriction
      • pylorus (adult hypertrophic)
        • newborn
    • Hypertrophy, hypertrophic
      • pylorus (adult) (muscle) (sphincter)
        • congenital or infantile
    • Obstruction, obstructed, obstructive
      • pylorus
        • congenital or infantile
    • Pylorospasm(reflex) NEC
      • congenital or infantile
    • Pylorospasm(reflex) NEC
      • newborn
    • Spasm(s), spastic, spasticity
      • pylorus NEC
        • congenital or infantile
    • Stenosis, stenotic(cicatricial)
      • pylorus (hypertrophic) (acquired)
        • congenital
    • Stenosis, stenotic(cicatricial)
      • pylorus (hypertrophic) (acquired)
        • infantile
    • Stricture
      • pylorus (hypertrophic)
        • congenital
    • Stricture
      • pylorus (hypertrophic)
        • infantile

Clinical ClassificationClinical

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

CCSR MAL002
Digestive congenital anomalies
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Pyloric Stenosis

    narrowing of the pyloric canal with varied etiology. a common form is due to muscle hypertrophy (pyloric stenosis, hypertrophic) seen in infants.

  • Pyloric Stenosis, Hypertrophic

    narrowing of the pyloric canal due to hypertrophy of the surrounding circular muscle. it is usually seen in infants or young children.

  • Hypertrophy

    general increase in bulk of a part or organ due to cell enlargement and accumulation of fluids and secretions, not due to tumor formation, nor to an increase in the number of cells (hyperplasia).

  • Pylorospasm

    involuntary spasms of the pylorus.

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 Q40.0 to ICD-9-CMHistory

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

ICD-9-CM
750.5 Cong pyloric stenosis
Exact Match The mapping is direct, with no qualifiers.

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 Q40.0Overview

Is Q40.0 (Other congenital malformations of upper alimentary tract) a billable code?

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

What MS-DRG does Q40.0 group to?

When congenital hypertrophic pyloric stenosis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 393, 394, 395, with relative weights from 0.6490 to 1.5993 depending on complications. Higher weights mean higher Medicare reimbursement.

Is Q40.0 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 congenital hypertrophic pyloric stenosis on inpatient claims.

What is the ICD-9 equivalent of Q40.0?

Under the General Equivalence Mappings, congenital hypertrophic pyloric stenosis converts to ICD-9-CM 750.5 (cong pyloric stenosis). The mapping is a direct match.

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.