2027 ICD-10-CM Diagnosis Code Q99.818Other Usher syndrome

ICD-10-CM Codes›Q00-Q99›Q90-Q99›Q99

ICD-10-CM Q99.818
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

Q99.818 is a billable ICD-10-CM diagnosis code for other Usher syndrome. 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. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 40 closely related codes. The code is exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Chromosomal abnormalities.

Code Identity

ICD-10-CM Code
Q99.818
Billable Status
Yes — Valid for Submission
Code Describes
Other Usher syndrome
Short Description
Other Usher syndrome
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 CodeQ99.818Other Usher syndrome

Present on Admission (POA)Billing

Q99.818 is exempt from POA reporting on inpatient claims to general acute care hospitals. Review the other POA exempt codes in Chromosomal abnormalities, not elsewhere classified (Q90-Q99).

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to Q99.818: its own notes plus those printed at Q99.81, block Q90-Q99, 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.

  • Usher syndrome, type 4

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 Block Q90-Q99 Chromosomal abnormalities, not elsewhere classified applies to 74 codes
  • mitochondrial metabolic disorders (E88.4-)
From Chapter 17 (Q00-QA1) Congenital malformations, deformations and chromosomal abnormalities applies to 900 codes
  • inborn errors of metabolism (E70-E88)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From Q99.81 Usher syndrome applies to 5 codes
  • code to identify any auditory and visual manifestations

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.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name Q99.818, its category, or a range that includes it.

Excludes1 4

These codes carry an Excludes1 note naming Q99.818: they are not reported together with it, unless the two conditions are unrelated.

  • E25 Adrenogenital disorders
    chromosomal abnormalities (Q90-Q99) names Q90-Q99, which includes this code
  • Block Q50-Q56 Congenital malformations of genital organs
    syndromes associated with anomalies in the number and form of chromosomes (Q90-Q99) names Q90-Q99, which includes this code
  • Q56 Indeterminate sex and pseudohermaphroditism
    pseudohermaphroditism with specified chromosomal anomaly (Q96-Q99) names Q96-Q99, which includes this code
  • Z15 Genetic susceptibility to disease
    chromosomal anomalies (Q90-Q99) names Q90-Q99, which includes this code

Code First 1

These codes say to code first a condition named in the note, and Q99.818 is one of the conditions named.

  • D84.81 Immunodeficiency due to conditions classified elsewhere
    chromosomal abnormalities (Q90-Q99) names Q90-Q99, which includes this code

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 MAL009
Chromosomal abnormalities
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Usher Syndromes

    autosomal recessive hereditary disorders characterized by congenital sensorineural hearing loss and retinitis pigmentosa. genetically and symptomatically heterogeneous, clinical classes include type i, type ii, and type iii. their severity, age of onset of retinitis pigmentosa and the degree of vestibular dysfunction are variable.

Code History & ChangesHistory

Replacement Q99.818 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 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About Q99.818Overview

What is the ICD-10 code for other Usher syndrome?

The ICD-10-CM code for other Usher syndrome is Q99.818 (sometimes written as Q99818). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is Q99.818 (Usher syndrome) a billable code?

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

What MS-DRG does Q99.818 group to?

When other Usher syndrome 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 Q99.818 a CC or MCC?

CMS lists Q99.818 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 40 closely related codes in its exclusion list.

Is Q99.818 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 other Usher syndrome on inpatient claims. The code appears in the Chromosomal abnormalities, not elsewhere classified (Q90-Q99) range of the CMS exempt list.