ICD-10 code for skull bone agenesis

The ICD-10-CM code for skull bone agenesis is Q75.8 (Other specified congenital malformations of skull and face bones). The official index lists 3 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on Q75.8.

Within Q75, choose Q75.8 (Other specified congenital malformations of skull and face bones) only when documentation doesn't support a more specific option: craniosynostosis (Q75.0), craniofacial dysostosis (Q75.1), Hypertelorism (Q75.2), Macrocephaly (Q75.3), Mandibulofacial dysostosis (Q75.4), Oculomandibular dysostosis (Q75.5) and congenital malformation of skull and face bones, unspecified (Q75.9).

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.