2027 ICD-10-CM Diagnosis Code N61.0Mastitis without abscess
ICD-10-CM Codes›N00–N99›N60-N65›N61
- Billable — Valid for Submission
- Not Chronic
N61.0 is a billable ICD-10-CM diagnosis code for mastitis without abscess. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 600 through 601. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nonmalignant breast conditions.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Actinobacillary mastitis
- Actinobacillus infection
- Acute adolescent mastitis
- Acute mastitis
- Acute non-puerperal breast abscess
- Acute non-puerperal mastitis
- Adolescent mastitis
- Breast infection
- Cellulitis of breast
- Cellulitis of pectoral region
- Coliform mastitis
- Corynebacterial mastitis
- Galactophoritis
- Infected gland of Montgomery
- Infective mastitis
- Inflammation of gland of Montgomery
- Inflammatory disorder of breast
- Mastitis of mumps
- Mycoplasma mastitis
- Nipple infection
- Nonpuerperal abscess of areola
- Nonpuerperal abscess of breast
- Nonpuerperal mastitis
- Nonpuerperal mastitis of left breast
- Nonpuerperal mastitis of right breast
- Obstetric infection of breast
- Obstetric mastitis
- Pseudomonas aeruginosa mastitis
- Retromammary mastitis
- Staphylococcal mastitis
- Subacute mastitis
- Subacute non-puerperal mastitis
- Subareolar mastitis
- Thelitis
- Ulcer of breast
- Ulcer of nipple
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to N61.0: its own notes plus those printed at N61, block N60-N65, and Chapter 14. 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.
- Infective mastitis (acute) (nonpuerperal) (subacute)
- Mastitis (acute) (nonpuerperal) (subacute) NOS
- Cellulitis (acute) (nonpuerperal) (subacute) of breast NOS
- Cellulitis (acute) (nonpuerperal) (subacute) of nipple NOS
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
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.
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name N61.0, its category, or a range that includes it.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
breast N61.0
mammary (gland) N61.0
Galactophoritis N61.0
Mammillitis N61.0
Mastitis (acute) (diffuse) (nonpuerperal) (subacute) N61.0
infective N61.0
without abscess N61.0
Thelitis N61.0
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Mastitis
inflammation of the breast, or mammary gland.
Patient EducationClinical
Breast Diseases
Breast diseases include various conditions and changes in your breast. Most women experience breast changes at some time. Your age, hormone levels, and medicines you take may cause lumps, bumps, and discharges of fluids that are not breast milk.
The full article covers:
- What are breast diseases?
- What are the symptoms of breast disease?
- How are breast diseases diagnosed?
- What are the treatments for breast disease?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert N61.0 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code History & ChangesHistory
Replacement N61.0 replaces the following previously assigned code(s):
- N61 - Inflammatory disorders of breast
Questions About N61.0Overview
What is the ICD-10 code for mastitis without abscess?
The ICD-10-CM code for mastitis without abscess is N61.0 (sometimes written as N610). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is N61.0 (Inflammatory disorders of breast) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report mastitis without abscess on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does N61.0 group to?
When mastitis without abscess is the principal diagnosis on an inpatient stay, it groups to MS-DRG 600, 601, with relative weights from 0.6014 to 0.9971 depending on complications. Higher weights mean higher Medicare reimbursement.
Can N61.0 be reported with a code from C50.A?
Not as a rule. The Excludes1 note at N61, which applies to N61.0, lists "inflammatory carcinoma of breast (C50.A-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What is the ICD-9 equivalent of N61.0?
Under the General Equivalence Mappings, mastitis without abscess converts to ICD-9-CM 611.0 (inflam disease of breast). The mapping is approximate, so confirm the match fits the documentation.
