ICD-10-CM 2027
ICD-10 code for Diaphysial aclasis
From the official ICD-10-CM alphabetic index entry “Diaphysial aclasis”. Page updated September 29, 2026.
About coding Diaphysial aclasis
The ICD-10-CM code for Diaphysial aclasis is Q78.6 (Multiple congenital exostoses).
Within Q78 (other osteochondrodysplasias), Q78.6 is specifically for multiple congenital exostoses. Related codes cover Osteogenesis imperfecta (Q78.0), Polyostotic fibrous dysplasia (Q78.1), Osteopetrosis (Q78.2), progressive diaphyseal dysplasia (Q78.3), Enchondromatosis (Q78.4), Metaphyseal dysplasia (Q78.5), other specified osteochondrodysplasias (Q78.8) and osteochondrodysplasia, unspecified (Q78.9).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 564 (Other Musculoskeletal System and Connective Tissue Diagnoses with MCC, relative weight 1.4908), DRG 565 (Other Musculoskeletal System and Connective Tissue Diagnoses with CC, relative weight 0.9783) and DRG 566 (Other Musculoskeletal System and Connective Tissue Diagnoses without CC/MCC, relative weight 0.7378), in MDC 08 (Diseases and Disorders of the Musculoskeletal System and Connective Tissue), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
Common questions about Diaphysial aclasis ICD-10 codes
What is the ICD-10 code for Diaphysial aclasis?
- Q78.6 — Multiple congenital exostoses.
Is Q78.6 billable?
- Yes. Q78.6 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can Q78.6 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict Q78.6 as a principal diagnosis.
Is Q78.6 a CC or MCC?
- No. Q78.6 is neither a CC nor an MCC under MS-DRG v44.0.