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ICD-10-CM 2027 diagnosis code

C55Malignant neoplasm of uterus, part unspecified

✓ Billable / specificFemale only

C55 is a valid, billable ICD-10-CM code for malignant neoplasm of uterus, part unspecified. 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 C55

C55 is the ICD-10-CM diagnosis code for malignant neoplasm of uterus, part unspecified. It belongs to block C51-C58 (malignant neoplasms of female genital organs) and chapter 2 (neoplasms). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

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 731 (Uterine and Adnexa Procedures for Malignancy with MCC, relative weight 3.5478), DRG 732 (Uterine and Adnexa Procedures for Malignancy with CC, relative weight 1.9208), DRG 733 (Uterine and Adnexa Procedures for Malignancy without CC/MCC, relative weight 1.4324), DRG 754 (Malignancy, Female Reproductive System with MCC, relative weight 1.8092), DRG 755 (Malignancy, Female Reproductive System with CC, relative weight 1.149) and DRG 756 (Malignancy, Female Reproductive System without CC/MCC, relative weight 0.8645), in MDC 13 (Diseases and Disorders of the Female 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 female patients (the sex-conflict edit itself was retired in FY2025).

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 179 (malignant neoplasm of uterus, part unspecified).

Notes that apply from higher levels

Instructions written at a parent level also apply to C55.

Broader instructions also apply from C51-C58 Malignant neoplasms of female genital organs and Chapter 2: Neoplasms.

Table of Drugs & Neoplasms entries

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

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  • 179Malignant neoplasm of uterus, part unspecifiedexact

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 C55

Is C55 billable?

Yes. C55 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can C55 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict C55 as a principal diagnosis.

Is C55 a CC or MCC?

No. C55 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does C55 group to?

C55 is used in the MS-DRG v44.0 logic for MS-DRG 731 (Uterine and Adnexa Procedures for Malignancy with MCC), MS-DRG 732 (Uterine and Adnexa Procedures for Malignancy with CC), MS-DRG 733 (Uterine and Adnexa Procedures for Malignancy without CC/MCC), MS-DRG 754 (Malignancy, Female Reproductive System with MCC), MS-DRG 755 (Malignancy, Female Reproductive System with CC) and MS-DRG 756 (Malignancy, Female Reproductive System 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 C55?

The CMS General Equivalence Mappings map C55 to ICD-9-CM 179.