Q16.5Congenital malformation of inner ear

Q16.5 is the ICD-10-CM diagnosis code for congenital malformation of inner ear. It belongs to category Q16 (congenital malformations of ear causing impairment of hearing), block Q10-Q18 (congenital malformations of eye, ear, face and neck) and chapter 17 (congenital malformations, deformations, chromosomal abnormalities, and genetic disorders). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within Q16 (congenital malformations of ear causing impairment of hearing), Q16.5 is specifically for congenital malformation of inner ear. Related codes cover congenital absence of (ear) auricle (Q16.0), congenital absence, atresia and stricture of auditory canal (external) (Q16.1), absence of eustachian tube (Q16.2), congenital malformation of ear ossicles (Q16.3), other congenital malformations of middle ear (Q16.4) and congenital malformation of ear causing impairment of hearing, unspecified (Q16.9).

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 154 (Other Ear, Nose, Mouth and Throat Diagnoses with MCC, relative weight 1.5921), DRG 155 (Other Ear, Nose, Mouth and Throat Diagnoses with CC, relative weight 0.9322) and DRG 156 (Other Ear, Nose, Mouth and Throat Diagnoses without CC/MCC, relative weight 0.6659), in MDC 03 (Diseases and Disorders of the Ear, Nose, Mouth and Throat), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It is exempt from present-on-admission (POA) reporting, so no POA indicator is required.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 744.05 (anomalies of inner ear).