2027 ICD-10-CM Diagnosis Code Q40.0Congenital hypertrophic pyloric stenosis
ICD-10-CM Codes›Q00-Q99›Q38-Q45›Q40
- Billable — Valid for Submission
- Risk Adjusts — HCC 78
- POA Exempt
- Chronic Condition
Q40.0 is a billable ICD-10-CM diagnosis code for congenital hypertrophic pyloric stenosis. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) 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.
For Medicare Advantage risk adjustment, Q40.0 maps to CMS-HCC Category 78 (Intestinal Obstruction/Perforation) under the V28 model, adding a risk factor of about 0.326 for a community, non-dual, aged beneficiary in payment year 2027.
Code Identity
Code Classification
Present on Admission (POA)Billing
Q40.0 is exempt from POA reporting on inpatient claims to general acute care hospitals. Review the other POA exempt codes in Other congenital malformations of the digestive system (Q38-Q45).
Medicare Risk Adjustment (HCC)Billing
Q40.0 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.
- 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
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to Q40.0: its own notes plus those printed at Chapter 17. A note printed at a category, block or chapter applies to every code under it.
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.
- Congenital constriction
- Congenital hypertrophy
- Congenital spasm
- Congenital stenosis
- Congenital stricture
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
Notes
General instructions on how these codes are used.
- Codes from this chapter are not for use on maternal records
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name Q40.0, its category, or a range that includes it.
Excludes1 3
These codes carry an Excludes1 note naming Q40.0: they are not reported together with it, unless the two conditions are unrelated.
Excludes2 1
These codes carry an Excludes2 note naming Q40.0: its condition is not part of those codes, and both may be reported when the patient has both.
- Block R10-R19 Symptoms and signs involving the digestive system and abdomencongenital or infantile pylorospasm (Q40.0)
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Constriction See Also: Stricture;
pylorus (adult hypertrophic) K31.1
congenital Q40.0
newborn Q40.0
Pylorospasm (reflex) NEC K31.3
congenital Q40.0
newborn Q40.0
Spasm (s), spastic, spasticity See Also: condition; R25.2
congenital Q40.0
Stenosis, stenotic (cicatricial) See Also: Stricture;
Stricture See Also: Stenosis;
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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.
Code History & ChangesHistory
Replaced This code was replaced in the FY 2027 code set by:
- K31.B - Hypertrophic pyloric stenosis, in childhood
Questions About Q40.0Overview
What is the ICD-10 code for congenital hypertrophic pyloric stenosis?
The ICD-10-CM code for congenital hypertrophic pyloric stenosis is Q40.0 (sometimes written as Q400). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
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, 2026 through September 30, 2027.
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 394, 395, 393, with relative weights from 0.6379 to 1.5877 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. The code appears in the Other congenital malformations of the digestive system (Q38-Q45) range of the CMS exempt list.
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.
What HCC is Q40.0?
Q40.0 (congenital hypertrophic pyloric stenosis) maps to CMS-HCC Category 78 (Intestinal Obstruction/Perforation), commonly written as HCC 78, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It does not map to any RxHCC in the Part D prescription drug model.
Does Q40.0 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, Q40.0 adds a risk adjustment factor of about 0.326 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.326 to 0.688 depending on the payment segment). A more severe related category (HCC 77) supersedes it when both are reported. See the full factor table on the HCC 78 category page.
