2026 ICD-10-CM Diagnosis Code Q79.8Other congenital malformations of musculoskeletal system

ICD-10-CM Codes›Q00-Q99›Q65-Q79›Q79

ICD-10-CM Q79.8
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Q79.8 is a billable ICD-10-CM diagnosis code for other congenital malformations of musculoskeletal system. 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
Q79.8
Billable Status
Yes — Valid for Submission
Code Describes
Other congenital malformations of musculoskeletal system
Short Description
Other congenital malformations of musculoskeletal system
Same as the full description in the CMS dataset.
Parent Code
Q79
Congenital malformations of musculoskeletal system, not elsewhere classified

Code Classification

ChapterQ00-Q99Congenital malformations, deformations and chromosomal abnormalities
SectionQ65-Q79Congenital malformations and deformations of the musculoskeletal system
CategoryQ79Congenital malformations of musculoskeletal system, not elsewhere classified
This CodeQ79.8Other congenital malformations of musculoskeletal system

Present on Admission (POA)Billing

Q79.8 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.

  • Aberrant forearm flexor muscle
  • Aberrant muscle of the upper limb
  • Accessory ossification center
  • Accessory skeletal muscle
  • Alopecia, onychodysplasia, hypohidrosis, deafness ectodermal dysplasia
  • Amyotrophia congenita
  • Angioosteohypotrophic syndrome
  • Aplasia of biceps brachii
  • Aplasia of muscle
  • Aplasia of muscle of abdominal wall
  • Aplasia of muscle of limb
  • Aplasia of muscle of pelvis
  • Aplasia of muscle of shoulder
  • Aplasia of muscle of thigh
  • Aplasia of muscle of upper arm
  • Aplasia of muscle of upper limb
  • Aplasia of pectoral muscle
  • Aplasia of pectoralis major muscle
  • Aplasia of quadriceps femoris muscle
  • Aplasia of triceps brachii
  • Autosomal dominant myopia, midfacial retrusion, sensorineural hearing loss, rhizomelic dysplasia syndrome
  • Bilateral muscle contracture of ankle regions
  • Bilateral muscle contracture of lower legs
  • Chondrolysis of articular cartilage
  • Congenital abnormal fusion of carpal bone
  • Congenital absence of abdominal muscle
  • Congenital absence of bilateral pectoral muscles
  • Congenital absence of left pectoral muscle
  • Congenital absence of muscle AND/OR tendon
  • Congenital absence of part of upper arm
  • Congenital absence of pectoral muscle
  • Congenital absence of quadriceps muscle
  • Congenital absence of right pectoral muscle
  • Congenital absence of skeletal bone
  • Congenital absence of skeletal muscle
  • Congenital absence of soft tissue of distal phalanx of finger
  • Congenital absence of tendon
  • Congenital amyoplasia
  • Congenital anomaly of body cavity
  • Congenital anomaly of cartilage
  • Congenital anomaly of hyoid bone
  • Congenital bilateral short Achilles tendons
  • Congenital chondrolysis
  • Congenital contracture of bilateral gastrocnemius
  • Congenital contracture of gastrocnemius muscle
  • Congenital contracture of left gastrocnemius muscle
  • Congenital contracture of right gastrocnemius muscle
  • Congenital dysplasia of bone caused by drug
  • Congenital hepatomegaly
  • Congenital hyperplasia of muscle
  • Congenital hypoplasia of biceps brachii muscle
  • Congenital hypoplasia of deltoid muscle
  • Congenital hypoplasia of hyoid bone
  • Congenital hypoplasia of latissimus dorsi muscle
  • Congenital hypoplasia of muscle of abdominal wall
  • Congenital hypoplasia of muscle of limb
  • Congenital hypoplasia of muscle of neck
  • Congenital hypoplasia of muscle of pelvis
  • Congenital hypoplasia of muscle of shoulder
  • Congenital hypoplasia of muscle of thigh
  • Congenital hypoplasia of muscle of upper arm
  • Congenital hypoplasia of muscle of upper limb
  • Congenital hypoplasia of pectoral muscle
  • Congenital hypoplasia of pectoralis major muscle
  • Congenital hypoplasia of pectoralis minor muscle
  • Congenital hypoplasia of posterior crural muscle
  • Congenital hypoplasia of quadriceps femoris muscle
  • Congenital hypoplasia of serratus anterior muscle
  • Congenital hypoplasia of triceps brachii muscle
  • Congenital muscular hypertrophy-cerebral syndrome
  • Congenital short Achilles tendon
  • Congenital short costocoracoid ligament
  • Congenital short left Achilles tendon
  • Congenital short quadriceps
  • Congenital short right Achilles tendon
  • Congenital shortening of tendon
  • Connective tissue disorder due to lysyl hydroxylase-3 deficiency
  • Constricting band of extremity
  • Constriction ring syndrome
  • Dermatoosteolysis Kirghizian type
  • Ectopic bone tissue, congenital
  • Geroderma osteodysplastica
  • Hadziselimovic syndrome
  • Hypoplasia of muscle
  • Incomplete ossification of hyoid bone
  • Intellectual disability, developmental delay, contracture syndrome
  • KBG syndrome
  • King Denborough syndrome
  • Micromelia
  • Muscle contracture of left ankle
  • Muscle contracture of right ankle
  • Muscular hypertrophy, hepatomegaly, polyhydramnios syndrome
  • Myostatin related hypertrophy of muscle
  • Poland anomaly
  • Polyneuropathy, intellectual disability, acromicria, premature menopause syndrome
  • Premature ovarian failure
  • Segmental progressive overgrowth syndrome with fibroadipose hyperplasia
  • Skeletal dysplasia
  • Thoracoceloschisis

Tabular List NotesGuidance

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

Inclusion Terms

  • Absence of muscle
  • Absence of tendon
  • Accessory muscle
  • Amyotrophia congenita
  • Congenital constricting bands
  • Congenital shortening of tendon
  • Poland syndrome

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)
      • muscle (congenital) (pectoral)
    • Absence(of) (organ or part) (complete or partial)
      • tendon (congenital)
    • Accessory(congenital)
      • bone NEC
    • Accessory(congenital)
      • muscle
    • Accessory(congenital)
      • tendon
    • Acromicria, acromikria
    • Agenesis
      • muscle
    • Agenesis
      • musculoskeletal system NEC
    • Agenesis
      • tendon
    • Amyoplasia congenita
    • Amyotrophia, amyotrophy, amyotrophic
      • congenita
    • Band(s)
      • constricting, congenital
    • Contraction(s), contracture, contracted
      • ligament
        • congenital
    • Contraction(s), contracture, contracted
      • muscle (postinfective) (postural) NEC
        • congenital
    • Diastasis
      • muscle
        • congenital
    • Dysplasia
      • muscle
    • Fusion, fused(congenital)
      • bone
    • Hypoplasia, hypoplastic
      • muscle
    • Krabbe's
      • syndrome, congenital muscle hypoplasia
    • Myelo-osteo-musculodysplasia hereditaria
    • Poland syndrome
    • Short, shortening, shortness
      • tendon
        • congenital
    • Supernumerary(congenital)
      • bone
    • Supernumerary(congenital)
      • muscle
    • Syndrome
      • Krabbe's congenital muscle hypoplasia
    • Syndrome
      • Touraine's
    • Thoracogastroschisis(congenital)
    • Touraine's syndrome

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 Q79.8 to ICD-9-CMHistory

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

ICD-9-CM
756.81 Absence of muscle/tendon
Approximate The match is approximate rather than exact.
ICD-9-CM
756.82 Accessory muscle
Approximate The match is approximate rather than exact.
ICD-9-CM
756.89 Soft tissue anomaly NEC
Approximate The match is approximate rather than exact.
ICD-9-CM
756.9 Musculoskel anom NEC/NOS
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 Q79.8Overview

Is Q79.8 a billable code?

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

What MS-DRG does Q79.8 group to?

When other congenital malformations of musculoskeletal system 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 Q79.8 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 other congenital malformations of musculoskeletal system on inpatient claims.

What is the ICD-9 equivalent of Q79.8?

Under the General Equivalence Mappings, other congenital malformations of musculoskeletal system converts to ICD-9-CM 756.81 (absence of muscle/tendon), 756.82 (accessory muscle), and 756.89 (soft tissue anomaly NEC). 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.