2027 ICD-10-CM Diagnosis Code Q78.6Multiple congenital exostoses

ICD-10-CM Codes›Q00-Q99›Q65-Q79›Q78

ICD-10-CM Q78.6
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

Q78.6 is a billable ICD-10-CM diagnosis code for multiple congenital exostoses. 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. The code is exempt from POA reporting. Coders also document this condition as anetoderma. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Musculoskeletal congenital conditions.

Code Identity

ICD-10-CM Code
Q78.6
Billable Status
Yes — Valid for Submission
Code Describes
Multiple congenital exostoses
Short Description
Multiple congenital exostoses
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 CodeQ78.6Multiple congenital exostoses

Present on Admission (POA)Billing

Q78.6 is exempt from POA reporting on inpatient claims to general acute care hospitals. Review the other POA exempt codes in Congenital malformations and deformations of the musculoskeletal system (Q65-Q79).

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Anetoderma
  • Congenital exostosis
  • Disorder characterized by multiple exostoses
  • Exostosis, anetoderma, brachydactyly type E syndrome
  • Multiple congenital exostosis

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to Q78.6: its own notes plus those printed at Q78 and Chapter 17. A note printed at a category, block or chapter applies to every code under it.

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • Diaphyseal aclasis

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.

From Q78 Other osteochondrodysplasias applies to 9 codes
  • congenital myotonic chondrodystrophy (G71.13)
From Chapter 17 (Q00-QA1) Congenital malformations, deformations and chromosomal abnormalities applies to 900 codes
  • inborn errors of metabolism (E70-E88)

Notes

General instructions on how these codes are used.

From Chapter 17 (Q00-QA1) Congenital malformations, deformations and chromosomal abnormalities applies to 900 codes
  • Codes from this chapter are not for use on maternal records

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

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

  • Exostoses, Multiple Hereditary

    hereditary disorder transmitted by an autosomal dominant gene and characterized by multiple exostoses (multiple osteochondromas) near the ends of long bones. the genetic abnormality results in a defect in the osteoclastic activity at the metaphyseal ends of the bone during the remodeling process in childhood or early adolescence. the metaphyses develop benign, bony outgrowths often capped by cartilage. a small number undergo neoplastic transformation.

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 Q78.6 to ICD-9-CMHistory

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

ICD-9-CM
756.59 Osteodystrophy 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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About Q78.6Overview

What is the ICD-10 code for multiple congenital exostoses?

The ICD-10-CM code for multiple congenital exostoses is Q78.6 (sometimes written as Q786). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is Q78.6 (Other osteochondrodysplasias) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report multiple congenital exostoses on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does Q78.6 group to?

When multiple congenital exostoses 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.

Is Q78.6 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 multiple congenital exostoses on inpatient claims. The code appears in the Congenital malformations and deformations of the musculoskeletal system (Q65-Q79) range of the CMS exempt list.

What is the ICD-9 equivalent of Q78.6?

Under the General Equivalence Mappings, multiple congenital exostoses converts to ICD-9-CM 756.59 (osteodystrophy NEC). The mapping is approximate, so confirm the match fits the documentation.