2027 ICD-10-CM Diagnosis Code O91.22Nonpurulent mastitis associated with the puerperium
ICD-10-CM Codes›O00-O9A›O85-O92›O91
- Billable — Valid for Submission
- Not Chronic
O91.22 is a billable ICD-10-CM diagnosis code for nonpurulent mastitis associated with the puerperium. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 769, 776. The code is restricted by the Medicare Code Editor to maternity cases (age 9 through 64). Coders also document this condition as difficulty latching on to breast for feeding. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Complications specified during the puerperium and Nonmalignant breast conditions.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for O91.22.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Difficulty latching on to breast for feeding
- Finding related to ability to latch on to breast for feeding
- Interstitial mastitis associated with childbirth
- Mastitis associated with lactation
- Nonpurulent mastitis associated with childbirth
- Nonpurulent mastitis associated with childbirth with attachment difficulty
- Obstetric non-purulent mastitis
- Parenchymatous mastitis associated with childbirth
- Postpartum mastitis
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to O91.22: its own notes plus those printed at O91, block O85-O92, and Chapter 15. 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.
- Puerperal interstitial mastitis
- Puerperal lymphangitis of breast
- Puerperal mastitis NOS
- Puerperal parenchymatous mastitis
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
- supervision of normal pregnancy (Z34.-)
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.
Use Additional Code
Add a second code, after this one, to fully describe the condition.
- code to identify infection
- code, if applicable, from category Z3A, Weeks of gestation, to identify the specific week of the pregnancy, if known.
Notes
General instructions on how these codes are used.
- CODES FROM THIS CHAPTER ARE FOR USE ONLY ON MATERNAL RECORDS, NEVER ON NEWBORN RECORDS
- Codes from this chapter are for use for conditions related to or aggravated by the pregnancy, childbirth, or by the puerperium (maternal causes or obstetric causes)
- Trimesters are counted from the first day of the last menstrual period. They are defined as follows:
- 1st trimester- less than 14 weeks 0 days
- 2nd trimester- 14 weeks 0 days to less than 28 weeks 0 days
- 3rd trimester- 28 weeks 0 days until delivery
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name O91.22, its category, or a range that includes it.
Excludes1 2
These codes carry an Excludes1 note naming O91.22: they are not reported together with it, unless the two conditions are unrelated.
- N61 Inflammatory disorders of breastinflammatory disorder of breast associated with childbirth (O91.-) names O91.-, which includes this code
- Block N60-N65 Disorders of breast
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Puerperal, puerperium (complicated by, complications)
galactophoritis O91.22
breast O91.22
mammitis O91.22
mastitis O91.22
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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 O91.22 to ICD-9-CMHistory
Code HistoryHistory
Questions About O91.22Overview
What is the ICD-10 code for nonpurulent mastitis associated with the puerperium?
The ICD-10-CM code for nonpurulent mastitis associated with the puerperium is O91.22 (sometimes written as O9122). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is O91.22 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report nonpurulent mastitis associated with the puerperium on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does O91.22 group to?
When nonpurulent mastitis associated with the puerperium is the principal diagnosis on an inpatient stay, it groups to MS-DRG 769, 776, with relative weights from 0.6718 to 1.6666 depending on complications. Higher weights mean higher Medicare reimbursement.
Who can O91.22 be reported for?
The Medicare Code Editor checks nonpurulent mastitis associated with the puerperium against patient demographics: this code is intended for maternity cases (age 9 through 64). Claims outside these limits are flagged as inconsistent.
Does O91.22 need an additional code?
When the condition applies, yes. The Use Additional Code note at O91, which applies to O91.22, reads: code to identify infection. The additional code is reported after O91.22.
