2026 ICD-10-CM Diagnosis Code Q99.819Usher syndrome, unspecified

ICD-10-CM Codes›Q00-Q99›Q90-Q99›Q99

ICD-10-CM Q99.819
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Q99.819 is a billable ICD-10-CM diagnosis code for usher syndrome, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 564 through 566. The code is exempt from POA reporting.

Code Identity

ICD-10-CM Code
Q99.819
Billable Status
Yes — Valid for Submission
Code Describes
Usher syndrome, unspecified
Short Description
Usher syndrome, unspecified
Same as the full description in the CMS dataset.
Parent Code
Q99.81
Usher syndrome

Code Classification

ChapterQ00-Q99Congenital malformations, deformations and chromosomal abnormalities
SectionQ90-Q99Chromosomal abnormalities, not elsewhere classified
CategoryQ99Other chromosome abnormalities, not elsewhere classified
This CodeQ99.819Usher syndrome, unspecified

Present on Admission (POA)Billing

Q99.819 is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Syndrome
      • usher

Clinical InformationClinical

  • Clarin-1|CLRN1|Clarin 1|Usher Syndrome Type-3 Protein

    clarin-1 (232 aa, ~26 kda) is encoded by the human clrn1 gene. this protein is involved in the organization of the cytoskeleton in photoreceptor and auditory receptor cells.

  • CLRN1 wt Allele|Clarin 1 wt Allele|RP61|USH3|USH3A|Usher Syndrome 3A Gene

    human clrn1 wild-type allele is located in the vicinity of 3q25.1 and is approximately 47 kb in length. this allele, which encodes clarin-1 protein, plays a role in sight and hearing. mutations in the gene are associated with usher syndrome 3a and retinitis pigmentosa 61.

  • HARS1 wt Allele|CMT2W|HARS|HRS|Histidine Translase Gene|Histidine tRNA Ligase 1, Cytoplasmic Gene|Histidyl-tRNA Synthetase 1 wt Allele|Histidyl-tRNA Synthetase Gene|Jo-1 Antigen Gene|USH3B|Usher Syndrome 3B Gene

    human hars1 wild-type allele is located in the vicinity of 5q31.3 and is approximately 19 kb in length. this allele, which encodes histidine-trna ligase, cytoplasmic protein, is involved in trna aminoacylation. mutation of the gene is associated with axonal charcot-marie-tooth disease type 2w and usher syndrome type 3b.

  • MYO7A wt Allele|DFNA11|DFNB2|MYOVIIA|MYU7A|Myosin VIIA (Usher Syndrome 1B (Autosomal Recessive, Severe)) Gene|Myosin VIIA wt Allele|Myosin, Unconventional Family VII, Member A Gene|NSRD2|USH1B

    human myo7a wild-type allele is located in the vicinity of 11q13.5 and is approximately 87 kb in length. this allele, which encodes unconventional myosin-viia protein, plays a role in intracellular transport affecting sight and hearing. mutations in the gene are associated with autosomal dominant deafness 11, autosomal recessive deafness 2 and usher syndrome type 1b.

  • USH1G Gene|USH1G|USH1G|Usher Syndrome 1G (Autosomal Recessive) Gene

    this gene plays a role in both sight and hearing.

  • USH1G wt Allele|ANKS4A|FLJ33924|SANS|Sans|Usher Syndrome 1G (Autosomal Recessive) wt Allele

    human ush1g wild-type allele is located in the vicinity of 17q25.1 and is approximately 7 kb in length. this allele, which encodes usher syndrome type-1g protein, is involved in the development of both the retina and cochlear hair cells. mutation of the gene is associated with usher syndrome 1g.

  • USH2A wt Allele|RP39|US2|USH2|Usher Syndrome 2A (Autosomal Recessive, Mild) Gene|Usherin wt Allele|dJ1111A8.1

    human ush2a wild-type allele is located in the vicinity of 1q41 and is approximately 801 kb in length. this allele, which encodes usherin protein, plays a role in hearing and sight. mutations in the gene are associated with retinitis pigmentosa 39 and usher syndrome type 2a.

  • Usher Syndrome

    a rare, autosomal recessive inherited syndrome caused by mutations in the cdh23, clrn1, gpr98, myo7a, pcdh15, ush1c, ush1g, and ush2a genes. it is characterized by hearing loss or deafness and progressive loss of vision. the loss of vision is the result of retinitis pigmentosa.

  • Usher Syndrome Type 1

    a syndrome characterized by congenital, bilateral, severe sensorineural hearing loss, abnormalities in the vestibular system, and adolescent-onset retinitis pigmentosa.

  • Usher Syndrome Type 2

    a syndrome characterized by congenital, bilateral sensorineural hearing loss that is mild to moderate in the low frequencies and severe to profound in the higher frequencies, no abnormalities in the vestibular system, and retinitis pigmentosa.

  • Usher Syndrome Type 2C|USH2C

    an autosomal recessive sub-type of usher syndrome caused by homozygous or compound heterozygous mutation(s) in the adgrv1 gene, encoding adhesion g protein-coupled receptor v1. it may also result from biallelic digenic mutation(s) in adgrv1 and pdzd7, which encodes pdz domain-containing protein 7.

  • Usher Syndrome Type 3

    a syndrome characterized by postlingual progressive hearing loss, abnormalities in the vestibular system, and onset of retinitis pigmentosa symptoms usually by the second decade of life.

  • Usher Syndrome Type-1G Protein|Scaffold Protein Containing Ankyrin Repeats and SAM Domain|USH1G

    usher syndrome type-1g protein (461 aa, ~51 kda) is encoded by the human ush1g gene. this protein plays a role in retinal and cochlear development.

  • Usherin|USH2A|Usher Syndrome Type IIa Protein|Usher Syndrome Type-2A Protein

    usherin (5202 aa, ~576 kda) is encoded by the human ush2a gene. this protein is involved in the functionality of cochlear hair cells and retinal photoreceptor cells.

Code History & ChangesHistory

New Code Q99.819 was added to the ICD-10-CM code set for FY 2026, effective October 1, 2025.

Replacement Q99.819 replaces the following previously assigned code(s):

  • Q99.8 - Other specified chromosome abnormalities
FY 2026AddedAdded to the ICD-10-CM code setEffective October 1, 2025.
FY 2026CurrentRevised in the current code setEffective October 1, 2025 through September 30, 2026.

Questions About Q99.819Overview

Is Q99.819 (Usher syndrome) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report usher syndrome, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does Q99.819 group to?

When usher syndrome, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 564, 565, 566, with relative weights from 0.7493 to 1.5436 depending on complications. Higher weights mean higher Medicare reimbursement.

Is Q99.819 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 usher syndrome, unspecified on inpatient claims.