2027 ICD-10-CM Diagnosis Code Q98.4Klinefelter syndrome, unspecified

ICD-10-CM Codes›Q00-Q99›Q90-Q99›Q98

ICD-10-CM Q98.4
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

Q98.4 is a billable ICD-10-CM diagnosis code for klinefelter syndrome, unspecified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 729 through 730. The code is exempt from POA reporting. Coders also document this condition as klinefelter syndrome. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Chromosomal abnormalities.

Code Identity

ICD-10-CM Code
Q98.4
Billable Status
Yes — Valid for Submission
Code Describes
Klinefelter syndrome, unspecified
Short Description
Klinefelter syndrome, unspecified
Same as the full description in the CMS dataset.
Parent Code
Q98
Other sex chromosome abnormalities, male phenotype, not elsewhere classified

Code Classification

ChapterQ00-Q99Congenital malformations, deformations and chromosomal abnormalities
SectionQ90-Q99Chromosomal abnormalities, not elsewhere classified
CategoryQ98Other sex chromosome abnormalities, male phenotype, not elsewhere classified
This CodeQ98.4Klinefelter syndrome, unspecified

Present on Admission (POA)Billing

Q98.4 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).

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Klinefelter syndrome

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to Q98.4: its own notes plus those printed at block Q90-Q99 and Chapter 17. A note printed at a category, block or chapter applies to every code under it.

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)

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 Q98.4, its category, or a range that includes it.

Excludes1 5

These codes carry an Excludes1 note naming Q98.4: they are not reported together with it, unless the two conditions are unrelated.

  • E29 Testicular dysfunction
    Klinefelter's syndrome (Q98.0-Q98.1, Q98.4)
  • 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 Q98.4 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

  • Klinefelter Syndrome

    a form of male hypogonadism, characterized by the presence of an extra x chromosome, small testes, seminiferous tubule dysgenesis, elevated levels of gonadotropins, low serum testosterone, underdeveloped secondary sex characteristics, and male infertility (infertility, male). patients tend to have long legs and a slim, tall stature. gynecomastia is present in many of the patients. the classic form has the karyotype 47,xxy. several karyotype variants include 48,xxyy; 48,xxxy; 49,xxxxy, and mosaic patterns ( 46,xy/47,xxy; 47,xxy/48,xxxy, etc.).

Patient EducationClinical

Klinefelter Syndrome

Klinefelter syndrome (KS) is a genetic condition that happens when a male is born with an extra copy of the X chromosome. KS can affect different stages of physical, language, and social development. It also usually causes infertility.

The full article covers:

  • What is Klinefelter syndrome (KS)?
  • What causes Klinefelter syndrome (KS)?
  • What are the symptoms of Klinefelter syndrome (KS)?
  • How is Klinefelter syndrome (KS) diagnosed?
  • What are the treatments for Klinefelter syndrome (KS)?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert Q98.4 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
758.7 Klinefelter's syndrome
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About Q98.4Overview

What is the ICD-10 code for klinefelter syndrome, unspecified?

The ICD-10-CM code for klinefelter syndrome, unspecified is Q98.4 (sometimes written as Q984). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is Q98.4 a billable code?

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

What MS-DRG does Q98.4 group to?

When klinefelter syndrome, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 729, 730, with relative weights from 0.6595 to 1.0553 depending on complications. Higher weights mean higher Medicare reimbursement.

Is Q98.4 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 klinefelter syndrome, unspecified on inpatient claims. The code appears in the Chromosomal abnormalities, not elsewhere classified (Q90-Q99) range of the CMS exempt list.

What is the ICD-9 equivalent of Q98.4?

Under the General Equivalence Mappings, klinefelter syndrome, unspecified converts to ICD-9-CM 758.7 (Klinefelter's syndrome). The mapping is approximate, so confirm the match fits the documentation.