Skip to content
Dx

ICD-10-CM 2027 diagnosis code

N61.20Granulomatous mastitis, unspecified breast

✓ Billable / specific

N61.20 is a valid, billable ICD-10-CM code for granulomatous mastitis, unspecified breast. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Code last changed in FY2021 (effective October 1, 2020). Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About N61.20

N61.20 is the ICD-10-CM diagnosis code for granulomatous mastitis, unspecified breast. It belongs to category N61 (inflammatory disorders of breast), block N60-N65 (disorders of breast) and chapter 14 (diseases of the genitourinary system). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within N61.2, choose N61.20 (unspecified breast) only when documentation doesn't support a more specific option: right breast (N61.21), left breast (N61.22) and bilateral breast (N61.23).

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 600 (Non-Malignant Breast Disorders with CC/MCC, relative weight 0.9975) and DRG 601 (Non-Malignant Breast Disorders without CC/MCC, relative weight 0.6017), in MDC 09 (Diseases and Disorders of the Skin, Subcutaneous Tissue and Breast), 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 was added in FY2021, effective October 1, 2020.

Notes that apply from higher levels

Instructions written at a parent level also apply to N61.20.

› From N61 Inflammatory disorders of breast
Excludes1
  • inflammatory carcinoma of breast (C50.A-)
  • inflammatory disorder of breast associated with childbirth (O91.-)
  • neonatal infective mastitis (P39.0)
  • thrombophlebitis of breast [Mondor's disease] (I80.8)

Broader instructions also apply from N60-N65 Disorders of breast and Chapter 14: Diseases of the genitourinary system.

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.

MDC 09 · Diseases and Disorders of the Skin, Subcutaneous Tissue and Breast

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
  • FY2021 (effective 10/1/2020): Added
  • No changes since FY2021.

Common questions about N61.20

Is N61.20 billable?

Yes. N61.20 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can N61.20 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict N61.20 as a principal diagnosis.

Is N61.20 a CC or MCC?

No. N61.20 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does N61.20 group to?

N61.20 is used in the MS-DRG v44.0 logic for MS-DRG 600 (Non-Malignant Breast Disorders with CC/MCC) and MS-DRG 601 (Non-Malignant Breast Disorders without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.