2026 ICD-10-CM Diagnosis Code Q78.2Osteopetrosis

ICD-10-CM Codes›Q00-Q99›Q65-Q79›Q78

ICD-10-CM Q78.2
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Q78.2 is a billable ICD-10-CM diagnosis code for osteopetrosis. 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
Q78.2
Billable Status
Yes — Valid for Submission
Code Describes
Osteopetrosis
Short Description
Osteopetrosis
Same as the full description in the CMS dataset.
Parent Code
Q78
Other osteochondrodysplasias

Code Classification

ChapterQ00-Q99Congenital malformations, deformations and chromosomal abnormalities
SectionQ65-Q79Congenital malformations and deformations of the musculoskeletal system
CategoryQ78Other osteochondrodysplasias
This CodeQ78.2Osteopetrosis

Present on Admission (POA)Billing

Q78.2 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.

  • Anhidrotic ectodermal dysplasia, immunodeficiency, osteopetrosis, lymphedema syndrome
  • Autosomal dominant osteopetrosis type 1
  • Autosomal dominant osteopetrosis type 2
  • Colobomatous microphthalmia
  • COMMAD syndrome
  • Complete deafness
  • Congenital deafness
  • Congenital hypogammaglobulinemia
  • Dentin dysplasia
  • Dentin dysplasia with sclerotic bone syndrome
  • Endosteal hyperostoses
  • Hypogammaglobulinemia
  • Infantile malignant osteopetrosis
  • Infantile osteopetrosis with neuroaxonal dysplasia syndrome
  • Lenz-Majewski hyperostosis syndrome
  • Osteochondrodysplasia with osteopetrosis
  • Osteomesopyknosis
  • Osteopathia striata
  • Osteopathia striata with cranial sclerosis
  • Osteopetrosis
  • Osteopetrosis - delayed type
  • Osteopetrosis - intermediate type
  • Osteopetrosis hypogammaglobulinemia syndrome
  • Osteopetrosis with renal tubular acidosis
  • Osteosclerosis
  • Osteosclerosis - Stanescu type
  • Osteosclerosis, developmental delay, craniosynostosis syndrome
  • Osteosclerotic metaphyseal dysplasia
  • Pathologic fracture of right foot due to osteopetrosis
  • Pathological fracture of foot due to osteopetrosis
  • Pathological fracture of left foot
  • Pathological fracture of left foot due to osteopetrosis
  • Pathological fracture of right foot
  • Sclerosteosis
  • Short stature disorder due to osteosclerosis
  • Specific antibody deficiency
  • Transient infantile osteopetrosis
  • Worth disease

Tabular List NotesGuidance

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

Inclusion Terms

  • Albers-Schönberg syndrome
  • Osteosclerosis NOS

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.

    • Albers-Schönberg syndrome
    • Disease, diseased
      • Albers-Schönberg (marble bones)
    • Ivory bones
    • Marble
      • bones
    • Osteopetrosis(familial)
    • Osteosclerosis
    • Osteosclerosis
      • fragilitas (generalisata)

Clinical ClassificationClinical

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

CCSR MAL008
Musculoskeletal congenital conditions
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Osteopetrosis

    excessive formation of dense trabecular bone leading to pathological fractures; osteitis; splenomegaly with infarct; anemia; and extramedullary hemopoiesis (hematopoiesis, extramedullary).

  • Dental Pulp Calcification

    calcinosis of the dental pulp or root canal.

  • Dentin Dysplasia

    an apparently hereditary disorder of dentin formation, marked by a normal appearance of coronal dentin associated with pulpal obliteration, faulty root formation, and a tendency for peripheral lesions without obvious cause. (from dorland, 27th ed)

  • Osteosclerosis

    an abnormal hardening or increased density of bone tissue.

  • Autosomal Dominant Osteopetrosis|Albers-Schonberg Disease|Autosomal Dominant Osteopetrosis Type 2|Benign Osteopetrosis|Marble Bone Disease

    an autosomal dominant form of osteopetrosis due to mutation(s) in the clcn7 gene, encoding h(+)/cl(-) exchange transporter 7. clinical features include sclerosis involving the spine, the pelvis, and the base of the skull. complications can include optic nerve compression, dental abscesses, anemia, and bone fragility. one third of individuals who carry a clcn7 mutation have a normal skeletal phenotype.

  • Autosomal Recessive Osteopetrosis 1|ARO1|Autosomal Recessive Albers-Schonberg Disease|Autosomal Recessive Marble Bones|Autosomal Recessive Osteopetrosis Type 1|Infantile Malignant Osteopetrosis 1|OPTB1

    a sub-type of autosomal recessive osteopetrosis caused by mutation(s) in the tcirg1 gene on chromosome 11q13, encoding the osteoclast-specific (alpha 3) subunit of the vacuolar proton pump. it is characterized by macrocephaly, frontal bossing, nystagmus, optic atrophy, blindness, deafness, and facial palsy.

  • Autosomal Recessive Osteopetrosis 8|OPTB8

    a sub-type of autosomal recessive osteopetrosis caused by mutation(s) in the snx10 gene, encoding sorting nexin-10.

  • Autosomal Recessive Osteopetrosis|Malignant Osteopetrosis

    an autosomal recessive form of osteopetrosis caused by mutation(s) in at least 8 genes related to osteoclast function. this condition is characterized by the failure of osteoclasts to resorb bone, resulting in impaired bone modeling/remodeling, and skeletal fragility despite increased bone mass; it is also associated with hematopoietic insufficiency, hypocalcemia, disturbed tooth eruption, nerve entrapment syndromes, and growth impairment. some cases are also associated with progressive neurological deterioration.

  • Osteoclast-Rich Osteopetrosis

    a form of osteopetrosis in which osteoclasts are abundant but have severely impaired resorptive function.

  • Osteopetrosis

    a rare genetic disorder inherited in an autosomal dominant, autosomal recessive, or x-linked recessive pattern. in the majority of cases it is caused by mutations in the clcn7, tcirg1, or ikbkg genes. it is characterized by excessive bone formation due to the failure of osteoclasts to resorb bone. it manifests with deformities, fractures, hepatosplenomegaly, anemia, and extramedullary hematopoiesis.

  • Osteopetrosis with Renal Tubular Acidosis|Autosomal Recessive Osteopetrosis 3|Autosomal Recessive Osteopetrosis, Type 3|Carbonic Anhydrase II Deficiency|Guibaud-Vainsel Syndrome|Marble Brain Disease|OPTB3

    a rare, autosomal recessive inherited disorder caused by mutation in the ca2 gene. it is characterized by osteopetrosis, renal tubular acidosis, and cerebral calcifications. it results in growth failure, mental retardation, and fractures.

  • Osteosclerosis

    abnormally high bone density.

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 Q78.2 to ICD-9-CMHistory

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

ICD-9-CM
756.52 Osteopetrosis
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 Q78.2Overview

Is Q78.2 (Other osteochondrodysplasias) a billable code?

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

What MS-DRG does Q78.2 group to?

When osteopetrosis 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 Q78.2 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 osteopetrosis on inpatient claims.

What is the ICD-9 equivalent of Q78.2?

Under the General Equivalence Mappings, osteopetrosis converts to ICD-9-CM 756.52 (osteopetrosis). 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.