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  6. 2025 ICD-10-CM Code O91
Version 2025
Non-Billable Code

2025 ICD-10-CM Diagnosis Code O91

Infections of breast associated with pregnancy, the puerperium and lactation

ICD-10-CM Code:
O91
ICD-10 Code for:
Infect of breast assoc w pregnancy, the puerp and lactation
Is Billable?
Not Valid for Submission
Code Navigator:

O91 is a non-specific and non-billable diagnosis code code, consider using a code with a higher level of specificity for a diagnosis of infections of breast associated with pregnancy, the puerperium and lactation. The code is not specific and is NOT valid for the year 2025 for the submission of HIPAA-covered transactions. Category or Header define the heading of a category of codes that may be further subdivided by the use of 4th, 5th, 6th or 7th characters.

Specific Coding Applicable to Infect of breast assoc w pregnancy, the puerp and lactation

Non-specific codes like O91 require more digits to indicate the appropriate level of specificity. Consider using any of the following ICD-10-CM codes with a higher level of specificity when coding for infect of breast assoc w pregnancy, the puerp and lactation:

  • O91.0 for Infection of nipple associated with pregnancy, the puerperium and lactation - NON-BILLABLE CODE

  • O91.01 for Infection of nipple associated with pregnancy - NON-BILLABLE CODE

  • Use O91.02 for Infection of nipple associated with the puerperium - BILLABLE CODE

  • Use O91.03 for Infection of nipple associated with lactation - BILLABLE CODE

  • O91.1 for Abscess of breast associated with pregnancy, the puerperium and lactation - NON-BILLABLE CODE

  • O91.11 for Abscess of breast associated with pregnancy - NON-BILLABLE CODE

  • Use O91.12 for Abscess of breast associated with the puerperium - BILLABLE CODE

  • Use O91.13 for Abscess of breast associated with lactation - BILLABLE CODE

  • O91.2 for Nonpurulent mastitis associated with pregnancy, the puerperium and lactation - NON-BILLABLE CODE

  • O91.21 for Nonpurulent mastitis associated with pregnancy - NON-BILLABLE CODE

  • Use O91.22 for Nonpurulent mastitis associated with the puerperium - BILLABLE CODE

  • Use O91.23 for Nonpurulent mastitis associated with lactation - BILLABLE CODE

Code Classification

  • Pregnancy, childbirth and the puerperium
    (O00-O9A)
    • Complications predominantly related to the puerperium
      (O85-O92)
      • Infections of breast associated with pregnancy, the puerperium and lactation
        (O91)

Tabular List of Diseases and Injuries

The following annotation back-references are applicable to this diagnosis code. The Tabular List of Diseases and Injuries is a list of ICD-10-CM codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more.


Use Additional Code

Use Additional Code
The “use additional code” indicates that a secondary code could be used to further specify the patient’s condition. This note is not mandatory and is only used if enough information is available to assign an additional code.
  • code to identify infection

Patient Education


Breast Diseases

Most women experience breast changes at some time. Your age, hormone levels, and medicines you take may cause lumps, bumps, and discharges (fluids that are not breast milk).

If you have a breast lump, pain, discharge or skin irritation, see your health care provider. Minor and serious breast problems have similar symptoms. Although many women fear cancer, most breast problems are not cancer.

Some common breast changes are:

  • Fibrocystic breast changes - lumpiness, thickening and swelling, often just before a woman's period
  • Cysts - fluid-filled lumps
  • Fibroadenomas - solid, round, rubbery lumps that move easily when pushed, occurring most in younger women
  • Intraductal papillomas - growths similar to warts near the nipple
  • Blocked milk ducts
  • Milk production when a woman is not breastfeeding

NIH: National Cancer Institute


[Learn More in MedlinePlus]

Breastfeeding

Breastfeeding offers many benefits to your baby. Breast milk contains the right balance of nutrients to help your infant grow into a strong and healthy toddler. Some of the nutrients in breast milk also help protect your infant against some common childhood illnesses and infections. It may also help your health. Certain types of cancer may occur less often in mothers who have breastfed their babies.

Women who don't have health problems should try to give their babies breast milk for at least the first six months of life. Most women with health problems can breastfeed. There are rare exceptions when women are advised not to breastfeed because they have certain illnesses. Some medicines, illegal drugs, and alcohol can also pass through the breast milk and cause harm to your baby. Check with your health care provider if you have concerns about whether you should breastfeed.

If you are having problems with breastfeeding, contact a lactation consultant.

NIH: National Institute of Child Health and Human Development


[Learn More in MedlinePlus]

Health Problems in Pregnancy

Every pregnancy has some risk of problems, but there are certain conditions and health issues that can raise that risk, such as:

  • A health condition you had before you got pregnant
  • A health condition you develop during pregnancy
  • A pregnancy with more than one baby
  • A health problem that happened during a previous pregnancy and could happen again
  • Substance use during pregnancy
  • Being over age 35

Any of these can affect your health, the health of your baby, or both.

If you have a chronic condition, you should talk to your health care provider about how to minimize your risk before you get pregnant. Once you are pregnant, you may need a health care team to monitor your pregnancy. Some common conditions that can complicate a pregnancy include:

  • High blood pressure
  • Kidney problems
  • Autoimmune diseases
  • Obesity
  • HIV
  • Cancer
  • Infections

Other conditions that may make pregnancy risky can develop during pregnancy - for example, gestational diabetes and Rh incompatibility. Good prenatal care can help detect and treat them.

Some symptoms, such as nausea, back pain, and fatigue, are common during pregnancy. Sometimes it is hard to know what is normal. Call your health care provider if something is bothering or worrying you.


[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.