2026 ICD-10-CM Diagnosis Code Q74.1Congenital malformation of knee

ICD-10-CM Codes›Q00-Q99›Q65-Q79›s

ICD-10-CM Q74.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Q74.1 is a billable ICD-10-CM diagnosis code for congenital malformation of knee. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 564 through 566. The code is exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Musculoskeletal congenital conditions.

Code Identity

ICD-10-CM Code
Q74.1
Billable Status
Yes — Valid for Submission
Code Describes
Congenital malformation of knee
Short Description
Congenital malformation of knee
Same as the full description in the CMS dataset.
Parent Code
Q74
Other congenital malformations of limb(s)

Code Classification

ChapterQ00-Q99Congenital malformations, deformations and chromosomal abnormalities
SectionQ65-Q79Congenital malformations and deformations of the musculoskeletal system
CategorysOther congenital malformations of limb (Q74)
This CodeQ74.1Congenital malformation of knee

Present on Admission (POA)Billing

Q74.1 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.

  • Absent patella
  • Aniridia and absent patella syndrome
  • Aplasia of patella
  • Bandy legged
  • Bifid patella
  • Bilateral congenital knee dislocation
  • Bilateral congenital patella dislocation
  • Bilateral disorder of patellofemoral joints
  • Blepharophimosis, intellectual disability syndrome/genitopatellar overlap syndrome
  • Congenital absence of patella
  • Congenital aniridia
  • Congenital anomaly of patella
  • Congenital deformity of bilateral knee joints
  • Congenital deformity of left knee joint
  • Congenital deformity of right knee joint
  • Congenital dislocation of left knee
  • Congenital dislocation of left patella
  • Congenital dislocation of patella
  • Congenital dislocation of right knee
  • Congenital dislocation of right patella
  • Congenital dysplasia of joint of knee
  • Congenital dysplasia of joint of left knee
  • Congenital dysplasia of joint of right knee
  • Congenital genu valgum
  • Congenital genu valgum of bilateral knees
  • Congenital genu valgum of left knee
  • Congenital genu valgum of right knee
  • Congenital genu varum
  • Congenital genu varum of bilateral knees
  • Congenital genu varum of left knee
  • Congenital genu varum of right knee
  • Congenital hypoplasia of patella
  • Coxopodopatellar syndrome
  • Dislocation of joint of knee due to congenital dysplasia of joint of knee
  • Dislocation of joint of left knee due to congenital dysplasia of joint of left knee
  • Dislocation of joint of right knee due to congenital dysplasia of joint of right knee
  • Ear, patella, short stature syndrome
  • Failure of tooth eruption
  • Genitopatellar syndrome
  • Hyperphalangy
  • Knee joint valgus deformity
  • Non-eruption of teeth, maxillary hypoplasia, genu valgum syndrome
  • Patella dysplasia
  • Scypho-patellar dysplasia
  • Triphalangeal thumb
  • Triphalangeal thumb and dislocation of patella syndrome

Tabular List NotesGuidance

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

Inclusion Terms

  • Congenital absence of patella
  • Congenital dislocation of patella
  • Congenital genu valgum
  • Congenital genu varum
  • Rudimentary patella

Type 1 Excludes

  • congenital dislocation of knee Q68.2
  • congenital genu recurvatum Q68.2
  • nail patella syndrome Q87.2

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)
      • patella, congenital
    • Agenesis
      • patella
    • Anomaly, anomalous(congenital) (unspecified type)
      • knee
    • Anomaly, anomalous(congenital) (unspecified type)
      • patella
    • Bifid(congenital)
      • patella
    • Biparta, bipartite
      • patella
    • Dislocation(articular)
      • patella
        • congenital
    • Elongated, elongation(congenital)
      • ligamentum patellae
    • Genu
      • congenital
    • Genu
      • extrorsum (acquired)
        • congenital
    • Genu
      • introrsum (acquired)
        • congenital
    • Genu
      • valgum (acquired) (knock-knee)
        • congenital
    • Genu
      • varum (acquired) (bowleg)
        • congenital
    • Hypertrophy, hypertrophic
      • meniscus, knee, congenital
    • Hypoplasia, hypoplastic
      • patella
    • Knock knee(acquired)
      • congenital
    • Malposition
      • congenital
        • patella
    • Rudimentary(congenital)
      • patella

Clinical ClassificationClinical

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

CCSR MAL008
Musculoskeletal congenital conditions
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 Q74.1 to ICD-9-CMHistory

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

ICD-9-CM
755.64 Cong knee deformity
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 Q74.1Overview

Is Q74.1 (Other congenital malformations of limb(s)) a billable code?

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

What MS-DRG does Q74.1 group to?

When congenital malformation of knee is the principal diagnosis on an inpatient stay, it groups to MS-DRG 564, 565, 566, with relative weights from 0.7493 to 1.5436 depending on complications. Higher weights mean higher Medicare reimbursement.

Is Q74.1 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 malformation of knee on inpatient claims.

What is the ICD-9 equivalent of Q74.1?

Under the General Equivalence Mappings, congenital malformation of knee converts to ICD-9-CM 755.64 (cong knee deformity). 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.