2026 ICD-10-CM Diagnosis Code M85.80Other specified disorders of bone density and structure, unspecified site

ICD-10-CM CodesM00–M99M80-M85M85

ICD-10-CM M85.80
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M85.80 is a billable ICD-10-CM diagnosis code for other specified disorders of bone density and structure, unspecified site. 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified bone disease and musculoskeletal deformities.

Code Identity

ICD-10-CM Code
M85.80
Billable Status
Yes — Valid for Submission
Code Describes
Other specified disorders of bone density and structure, unspecified site
Short Description
Oth disrd of bone density and structure, unspecified site
Parent Code
Other specified disorders of bone density and structure

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM80-M85Disorders of bone density and structure
CategoryM85Other disorders of bone density and structure
This CodeM85.80Other specified disorders of bone density and structure, unspecified site

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acroosteolysis
  • Apophyseal sclerosis
  • Bone density above reference range
  • Craniofacial dysplasia osteopenia syndrome
  • Disorder with defective osteoid mineralization
  • Dysplasia with decreased bone density
  • Dysplasia with increased bone density
  • Erosion of bone
  • Global developmental delay, osteopenia, ectodermal defect syndrome
  • Hereditary cerebellar atrophy
  • Hyperosteoidosis
  • Idiopathic acroosteolysis
  • Idiopathic acroosteolysis of phalanx
  • Melorheostosis
  • Melorheostosis with osteopoikilosis
  • Metabolic bone disease of prematurity
  • Neonatal osteopenia
  • Neurodevelopmental delay, seizures, ophthalmic anomalies, osteopenia, cerebellar atrophy syndrome
  • Occupational acroosteolysis
  • Osteopenia
  • Osteopenia caused by drug
  • Osteopenia due to disuse
  • Osteopenia of prematurity
  • Osteopenia with high fracture risk
  • Osteopenia, intellectual disability, sparse hair syndrome
  • Osteopoikilosis
  • Postmenopausal osteopenia
  • Premenopausal idiopathic osteopenia
  • Senile osteopenia
  • Steroid-induced osteopenia

Clinical ClassificationClinical

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

CCSR MUS028
Other specified bone disease and musculoskeletal deformities
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Melorheostosis

    a form of osteosclerosis extending in a linear track mainly through one of the long bones of the upper and lower limbs.
  • Osteopoikilosis

    an asymptomatic, autosomal dominant trait in which pea-sized sclerotic spots, prominent in the metaphyseal area, are accompanied by unique cutaneous lesions. these are yellowish papules or plaques with increased elastin content. (from cecil textbook of medicine, 19th ed, pp1434-35)
  • Acroosteolysis

    a condition that is characterized by degeneration of the distal phalanges.
  • Melorheostosis

    a very rare bone disorder characterized by thickening of the cortex in a linear pattern. signs and symptoms include joint pain, joint swelling, limb deformity, and changes in the skin covering the bone lesion.
  • Osteopoikilosis

    a rare autosomal dominant inherited disorder characterized by the presence of small areas of increased density throughout the bones.

Patient EducationClinical

Bone Density

Your bones are made of living tissue. To keep them strong, your body breaks down old bone and replaces it with new bone. But when more bone is broken down than replaced, you lose bone density, also called bone mass. Bone density is a measure of the amount of calcium and other minerals in bone. Bones containing more minerals are denser.

The full article covers:

  • What is bone density?
  • What can make you lose bone density?
  • Is there a test to measure your bone health?
  • How can I keep my bones strong?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert M85.80 to ICD-9-CMHistory

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

ICD-9-CM
733.90 Bone & cartilage dis NOS
Approximate The match is approximate rather than exact.
ICD-9-CM
733.99 Bone & cartilage dis NEC
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 M85.80Overview

Is M85.80 (Other specified disorders of bone density and structure) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other specified disorders of bone density and structure, unspecified site on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does M85.80 group to?

When other specified disorders of bone density and structure, unspecified site 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.

What is the ICD-9 equivalent of M85.80?

Under the General Equivalence Mappings, other specified disorders of bone density and structure, unspecified site converts to ICD-9-CM 733.90 (bone & cartilage dis NOS) and 733.99 (bone & cartilage dis NEC). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.