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ICD-10-CM 2027 diagnosis code

Q98.8Other specified sex chromosome abnormalities, male phenotype

✓ Billable / specificPOA exemptMale only

Q98.8 is a valid, billable ICD-10-CM code for other specified sex chromosome abnormalities, male phenotype. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About Q98.8

Q98.8 is the ICD-10-CM diagnosis code for other specified sex chromosome abnormalities, male phenotype. It belongs to category Q98 (other sex chromosome abnormalities, male phenotype, not elsewhere classified), block Q90-Q99 (chromosomal abnormalities, not elsewhere classified) 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 Q98, choose Q98.8 (Other specified sex chromosome abnormalities, male phenotype) only when documentation doesn't support a more specific option: Klinefelter syndrome karyotype 47, XXY (Q98.0), Klinefelter syndrome, male with more than two X chromosomes (Q98.1), other male with 46, XX karyotype (Q98.3), Klinefelter syndrome, unspecified (Q98.4), karyotype 47, XYY (Q98.5), male with structurally abnormal sex chromosome (Q98.6), male with sex chromosome mosaicism (Q98.7) and sex chromosome abnormality, male phenotype, unspecified (Q98.9).

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 729 (Other Male Reproductive System Diagnoses with CC/MCC, relative weight 1.0544) and DRG 730 (Other Male Reproductive System Diagnoses without CC/MCC, relative weight 0.6597), in MDC 12 (Diseases and Disorders of the Male Reproductive System), 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 on the CMS list of diagnoses consistent only with male patients (the sex-conflict edit itself was retired in FY2025).

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 758.81 (other conditions due to sex chromosome anomalies).

Notes that apply from higher levels

Instructions written at a parent level also apply to Q98.8.

Broader instructions also apply from Q90-Q99 Chromosomal abnormalities, not elsewhere classified and Chapter 17: Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders.

Alphabetic index entries

2 entries

Terms in the official ICD-10-CM index that lead to Q98.8.

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

ICD-9-CM equivalent

Converter →
  • 758.81Other conditions due to sex chromosome anomaliesapproximate

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about Q98.8

Is Q98.8 billable?

Yes. Q98.8 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can Q98.8 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict Q98.8 as a principal diagnosis.

Is Q98.8 a CC or MCC?

No. Q98.8 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does Q98.8 group to?

Q98.8 is used in the MS-DRG v44.0 logic for MS-DRG 729 (Other Male Reproductive System Diagnoses with CC/MCC) and MS-DRG 730 (Other Male Reproductive System Diagnoses without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

What is the ICD-9 code for Q98.8?

The CMS General Equivalence Mappings map Q98.8 to ICD-9-CM 758.81.