2027 ICD-10-CM Diagnosis Code M85.879Other specified disorders of bone density and structure, unspecified ankle and foot
ICD-10-CM Codes›M00–M99›M80-M85›M85
- Billable — Valid for Submission
- Not Chronic
M85.879 is a billable ICD-10-CM diagnosis code for other specified disorders of bone density and structure, unspecified ankle and foot. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) 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
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Dual energy X-ray absorptiometry abnormal
- Dual energy X-ray absorptiometry of calcaneum result osteopenia
- Melorheostosis of ankle region
- Quantitative ultrasound scan of heel - result osteopenic
- Sclerosis of bone of foot
- Sclerosis of distal phalanx of fifth toe
- Sclerosis of distal phalanx of foot
- Sclerosis of distal phalanx of fourth toe
- Sclerosis of distal phalanx of great toe
- Sclerosis of distal phalanx of second toe
- Sclerosis of distal phalanx of third toe
- Sclerosis of first metatarsal
- Sclerosis of middle phalanx of fifth toe
- Sclerosis of middle phalanx of foot
- Sclerosis of middle phalanx of fourth toe
- Sclerosis of middle phalanx of second toe
- Sclerosis of middle phalanx of third toe
- Sclerosis of phalanx of fifth toe
- Sclerosis of phalanx of foot
- Sclerosis of phalanx of fourth toe
- Sclerosis of phalanx of great toe
- Sclerosis of phalanx of second toe
- Sclerosis of phalanx of third toe
- Sclerosis of proximal phalanx of fifth toe
- Sclerosis of proximal phalanx of foot
- Sclerosis of proximal phalanx of fourth toe
- Sclerosis of proximal phalanx of great toe
- Sclerosis of proximal phalanx of second toe
- Sclerosis of proximal phalanx of third toe
- Sclerosis of tarsal bone
- Structural abnormality of distal phalanx of fifth toe
- Structural abnormality of distal phalanx of foot
- Structural abnormality of distal phalanx of fourth toe
- Structural abnormality of distal phalanx of great toe
- Structural abnormality of distal phalanx of second toe
- Structural abnormality of distal phalanx of third toe
- Structural abnormality of epiphysis of bone of foot
- Structural abnormality of epiphysis of phalanx of fifth toe
- Structural abnormality of epiphysis of phalanx of fourth toe
- Structural abnormality of epiphysis of phalanx of great toe
- Structural abnormality of epiphysis of phalanx of second toe
- Structural abnormality of epiphysis of phalanx of third toe
- Structural abnormality of epiphysis of phalanx of toe
- Structural abnormality of middle phalanx of fifth toe
- Structural abnormality of middle phalanx of fourth toe
- Structural abnormality of middle phalanx of lesser toe
- Structural abnormality of middle phalanx of second toe
- Structural abnormality of middle phalanx of third toe
- Structural abnormality of phalanx of fifth toe
- Structural abnormality of phalanx of fourth toe
- Structural abnormality of phalanx of great toe
- Structural abnormality of phalanx of second toe
- Structural abnormality of phalanx of third toe
- Structural abnormality of phalanx of toe
- Structural abnormality of proximal phalanx of fifth toe
- Structural abnormality of proximal phalanx of foot
- Structural abnormality of proximal phalanx of fourth toe
- Structural abnormality of proximal phalanx of great toe
- Structural abnormality of proximal phalanx of second toe
- Structural abnormality of proximal phalanx of third toe
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to M85.879: its own notes plus those printed at M85.8, M85, and Chapter 13. A note printed at a category, block or chapter applies to every code under it.
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
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.
- arthropathic psoriasis (L40.5-)
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- compartment syndrome (traumatic) (T79.A-)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Notes
General instructions on how these codes are used.
- Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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 M85.879 to ICD-9-CMHistory
Code HistoryHistory
Questions About M85.879Overview
Is M85.879 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 ankle and foot on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does M85.879 group to?
When other specified disorders of bone density and structure, unspecified ankle and foot is the principal diagnosis on an inpatient stay, it groups to MS-DRG 564, 566, 565, with relative weights from 0.7374 to 1.4909 depending on complications. Higher weights mean higher Medicare reimbursement.
Can M85.879 be reported with M48.1?
Not as a rule. The Excludes1 note at M85.8, which applies to M85.879, lists "diffuse idiopathic skeletal hyperostosis [DISH] (M48.1)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What is the ICD-9 equivalent of M85.879?
Under the General Equivalence Mappings, other specified disorders of bone density and structure, unspecified ankle and foot 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.
