ICD-10-CM Diagnosis Code O23.521 - Salpingo-oophoritis in pregnancy, first trimester (original) (raw)

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ICD List 2025-2026 Edition

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Salpingo-oophoritis in pregnancy, first trimester

ICD-10-CM Code:

O23.521

ICD-10 Code for:

Salpingo-oophoritis in pregnancy, first trimester

Is Billable?

Yes - Valid for Submission

Chronic Condition Indicator: [1]

Not chronic

Code Navigator:

O23.521 is a billable diagnosis code used to specify a medical diagnosis of salpingo-oophoritis in pregnancy, first trimester. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2025 through September 30, 2026.

The code O23.521 is applicable to female patients aged 12 through 55 years inclusive. It is clinically and virtually impossible to use this code on a non-female patient outside the stated age range.

This medical diagnosis code is frequently used in OB/GYN medical specialties to designate conditions such maternal disorders related to pregnancy.

  1. Code Information
  2. Clinical Classification
  3. Tabular List of Diseases and Injuries
  4. Code Edits
  5. Diagnostic Related Groups Mapping
  6. Convert to ICD-9 Code
  7. Patient Education
  8. Other Codes Used Similar Conditions
  9. Code History

Clinical Classifications group individual ICD-10-CM diagnosis codes into broader, clinically meaningful categories. These categories help simplify complex data by organizing related conditions under common clinical themes.

They are especially useful for data analysis, reporting, and clinical decision-making. Even when diagnosis codes differ, similar conditions can be grouped together based on their clinical relevance. Each category is assigned a unique CCSR code that represents a specific clinical concept, often tied to a body system or medical specialty.

CCSR Code: PRG028

Inpatient Default: Y - Yes, default inpatient assignment for principal diagnosis or first-listed diagnosis.

Outpatient Default: Y - Yes, default outpatient assignment for principal diagnosis or first-listed diagnosis.

The Medicare Code Editor (MCE) detects errors and inconsistencies in ICD-10-CM diagnosis coding that can affect Medicare claim validity. These Medicare code edits help medical coders and billing professionals determine when a diagnosis code is not appropriate as a principal diagnosis, does not meet coverage criteria. Use this list to verify whether a code is valid for Medicare billing and to avoid claim rejections or denials due to diagnosis coding issues.

The Medicare Code Editor detects inconsistencies in maternity cases by checking a patient's age and any diagnosis on the patient's record. The maternity code edits apply to patients age ange is 9–64 years inclusive (e.g., diabetes in pregnancy, antepartum pulmonary complication).

Below are the ICD-9 codes that most closely match this ICD-10 code, based on the General Equivalence Mappings (GEMs). This ICD-10 to ICD-9 crosswalk tool is helpful for coders who need to reference legacy diagnosis codes for audits, historical claims, or approximate code comparisons.

ICD-9-CM: 646.61

Approximate Flag - The approximate mapping means this ICD-10 code does not have an exact ICD-9 equivalent. The matched code is the closest available option, but it may not fully capture the original diagnosis or clinical intent.

ICD-9-CM: 646.63

Approximate Flag - The approximate mapping means this ICD-10 code does not have an exact ICD-9 equivalent. The matched code is the closest available option, but it may not fully capture the original diagnosis or clinical intent.

Infections and Pregnancy

How can infections affect your pregnancy?

During pregnancy, some common infections such as the common cold or a skin infection do not usually cause serious problems. Some infections, such as the flu, can be more severe when you're pregnant. But other infections can be harmful to you, your fetus, or both.

Certain infections during pregnancy may lead to or cause complications or health problems for your fetus, such as:

What infections can be harmful during pregnancy?

Some infections that can be harmful during pregnancy include:

What are the symptoms of an infection during pregnancy?

Sometimes, it's hard to know what's normal during pregnancy. Symptoms of an infection can vary based on the infection. Talk with your health care provider about what symptoms to look for and how to keep healthy. But, if something is worrying you, share your symptoms with your provider for early detection and treatment of infections.

What are the treatments for infections during pregnancy?

If you do get an infection during pregnancy, contact your provider about treatment that will best protect you and your fetus. Only some medicines are safe during pregnancy.

Can infections during pregnancy be prevented?

Taking care of yourself and getting early and regular prenatal care from your provider may help identify and treat infections early.

To lower your risk of certain infections or prevent others:

Department of Health and Human Services, Office on Women's Health

[Learn More in MedlinePlus]

Pelvic Inflammatory Disease

What is pelvic inflammatory disease?

Pelvic inflammatory disease (PID) is an infection of the uterus, ovaries, and other female reproductive organs. PID causes scarring in these organs. This can lead to infertility, ectopic pregnancy, pelvic pain, abscesses (a collection of pus), and other serious problems. PID is the most common preventable cause of infertility in the United States.

What causes pelvic inflammatory disease?

Many types of bacteria can cause PID, but it's often caused by sexually transmitted infections (STIs). Gonorrhea and chlamydia are the most common causes of PID.

You are at greater risk for PID if you:

It's not as common, but sometimes using an intrauterine device (IUD) for birth control can increase your risk for PID. However, your risk is usually only during the first three weeks after the IUD is placed inside your uterus.

What are the symptoms of pelvic inflammatory disease?

If you have PID, you may have mild or no symptoms. If you do have symptoms, the most common symptom is pain in the lower abdomen (belly). Other symptoms can include:

See your health care provider if you have any symptoms of PID or if you think you or your partner were exposed to an STI. Early treatment is important. Waiting too long for treatment increases the risk of infertility.

How is pelvic inflammatory disease diagnosed?

There is no one test for PID. To check for PID, your provider may:

What is the treatment for pelvic inflammatory disease?

Antibiotics are used to treat PID. You must take all the medicine, even if your symptoms go away to make sure the infection is cured. You will likely need to follow up with your provider to make sure the treatment is working.

Tell your recent sex partner(s) so they can get tested and treated. Don't have sex until you finish treatment, otherwise you can reinfect each other.

If you're pregnant, have an abscess, or your symptoms don't go away, you may need to have surgery or be hospitalized for treatment.

Treatment cannot fix any permanent damage already done to your internal organs.

If you don't get treated, complications can occur, such as:

Can pelvic inflammatory disease be prevented?

The best way to protect yourself against STIs is not to have sex.

If you do decide to have sex, a few ways you can lower your risk include to:

[Learn More in MedlinePlus]