What is OAB? Coding for Overactive Bladder ICD 9

Touseef Riaz

November 9, 2021

overactive bladder

From October 1, 2015, the US healthcare system formally transitioned to the International Classification of Diseases 10th revision, effectively replacing the ICD 9 which was formally being applied for documentation and reimbursement purposes. In contrast to the ICD 9, the new code set had a completely revamped structure and expanded greatly on the previous specific conditions and diseases.

Coding for Overactive Bladder ICD 10

When coding for OAB, the first thing to specify is what is the ICD 10 for active bladder.

According to the code set, N32.81 is the billable ICD 10 code for overactive bladder, which is also applicable to detrusor muscle hyperactivity. Cases that have been diagnosed with frequent urination due to a specified bladder condition should be excluded from N32.81

The following codes above N32.81 contain annotation back-references that may be applicable to N32.81:

  • N00-N99 – Diseases of the genitourinary system
  • N30-N39 – Other diseases of the urinary system
  • N32 – Other disorders of the bladder

The ICD 10 guidelines also define the approximate synonyms for the code, which are detrusor hyperreflexia are bladder muscle dysfunction – overactive.

The new ICD 10 code set incorporated new billing rules and code types that are important to get familiar with for correct coding. The change posed some challenges for the billing staff and the healthcare providers, which continues to impact the work to this day. In this article, we take a look at one of the most prevalent conditions that a urologist is faced with, overactive bladder, how the medical billing process is affected by the transition to overactive bladder ICD 10 and the correct ways to code cases for the disease.

Determining the Correct Overactive Bladder ICD 10 code

Since the overactive bladder is oftentimes confused with other types of urinary incontinence, it is important to have a clear understanding of the differences between them and the specific ICD 10 codes they are assigned to avoid any coding errors. Here are some of the most common types of incontinence and their corresponding ICD 10 codes.

Stress urinary incontinence – (N39.3)

This is the most common type of incontinence, characterized by an involuntary loss of urine caused by an increase in abdominal pressure.

Urge urinary incontinence – (N39.41)

This is described as when the patients have a sudden urge to urinate but are unable to keep control of their bladder. Elderly people are more prone to this type and is associated with detrusor muscle hyperactivity.

Mixed urinary incontinence – (N39.46)

This is diagnosed in patients who show symptoms of both stress and urge incontinence.

Overactive bladder – (N32.81)

OAB can be described as having urge incontinence but without any urine leak. The patients have an abnormally frequent need to go to the bathroom but can usually make it in time.

Significance of the ICD 10

The codes in the ICD 10 are much more granular than their predecessor, providing detailed information about the disease and patient’s condition.

The move to ICD-10-CM from ICD-9-CM was also necessitated by the fact that the latter was running out of code capacity to expand, as most of the code categories were completely full. Additionally, ICD-9-CM codes lacked the specificity and detail provided by ICD-10-CM.


Overactive bladder, or OAB, is a condition that is characterized by a sudden and frequent urge to urinate that is often difficult to control. It is common to observe an unintentional loss of urine, or urinary incontinence and the patient may pass urine several times a day.

People with an overactive bladder may feel that they are considerably handicapped in their daily life, and most of the time they feel embarrassed to even seek medical attention for it. However, a short trip to the doctor can help diagnose the underlying cause and provide treatment for the active symptoms.

Overactive bladder can be managed by basic behavioral changes in one’s lifestyle, like changes in diet, pelvic floor exercises and bladder holding techniques. The healthcare provider can always prescribe additional treatments if the initial efforts do not help.


In normal conditions, the brain sends signals to the bladder when it identifies that the bladder is full of urine. The bladder muscles then squeeze to allow the urine to pass through the urethra and reach the sphincter muscles that open to allow the urine to flow out.

With an overactive bladder, the signals that are sent to the bladder signaling a full bladder are disturbed which means that the person cannot be notified in time in case of a full bladder. There is only a sudden urge to go at the last time, sometimes happening even if the bladder is not full.

This happens when the nerve signals connecting the brain and bladder do not work properly. Due to the fluctuating signals, the brain may tell the bladder to empty, even if the bladder is not full yet. Another cause of an overactive bladder is when the muscles in the bladder are more active than normal. This causes the bladder to contract and pass urine before the bladder is full.


When a patient shares their symptoms with a healthcare provider, the provider would perform an exam to determine the cause. In some cases, the provider may refer to a urologist who specializes in diagnosing and treatment of overactive bladder.

A medical exam with a urologist starts off with question and answers sessions to better understand your health history and past experiences. The patient should ideally inform the provider about the symptoms you have, the duration of the issue and the effects it has on their lives. The patient should also clearly mention the prescription drugs and medicines that they have been taking.

After getting a detailed overview of the patient’s medical history, the urologist would move towards a physical exam to find out the cause behind the symptoms. This includes a physical examination of the organs in the pelvis, abdomen and rectum.

In some cases, the provider also asks the patients to keep a bladder diary for a few weeks to help determine the frequency of going to the bathroom as well as the times that the patient leaks urine. This helps to paint a clear picture of the symptoms.

Additional tests that a healthcare provider can resort to include:

  • Urine test: A urine sample is taken to test for blood or infection.
  • Bladder scan: This is an ultrasound to check the amount of urine left in the bladder after visiting the bathroom.

Healthcare Providers Who Treat Overactive Bladder

There are several healthcare providers that provide varying treatment for overactive bladder, and it is important for all of them to be familiar and well versed with the coding for ICD 10 overactive bladder, including:

  • Primary Care Practitioners: PCPs are doctors that treat common health problems and ailments. They are normally aware and experienced in the symptoms of overactive bladder and suggest treatment if the issue is not serious.
  • Urologist: Urologists are health specialists who treat and evaluate conditions related to the urinary tract. Most urologists are well experienced in incontinence, but not all specialize in the treatment of overactive bladder.
  • Gynecologists: Gynecologists are doctors who specialize in women’s health. Since the overactive bladder is found to affect women more than men, they are usually able to treat incontinence and overactive bladder.
  • Geriatricians: These are doctors who treat older patients and many are able to evaluate and treat overactive bladder.
  • Physical Therapists: These are licensed healthcare professionals providing physical therapy. If they have special training in pelvic floor disorders, they can help with exercises and lifestyle changes for overactive bladder.

About the ICD 10

The International Classification of Diseases, the tenth revision is a clinical system applied by healthcare providers and physicians to code and classify the diseases, diagnoses, symptoms and procedures that are recorded during health care provided. The ICD 10 is important to compile diagnostic specificity and morbidity data in the US.

The International Classification of Diseases is published by the World Health Organization, used by physicians, health information managers, coders, nurses and other professionals associated with the healthcare sector for storage and retrieval of information relating to diagnosis. In the bigger picture, the data is compiled to provide national morbidity and mortality statistics.

The ICD 10 comprises known disease and health problems listed in a systematic way and uses unique alphanumeric codes that correspond to each disease and condition to make identification easy. After the ICD 10 was formally regulated in the US health system, all HIPAA (Health Insurance Portability and Accountability Act) compliant/covered entities are required to adhere to the ICD 10 code sets.

Final Thoughts

The transition from ICD 9 to ICD 10 did not only serve the purpose of expanding the previous codes, but it also gave much more specificity when it comes to coding. It is a completely unique system with new rules, structure and language that is required by the medical and billing staff to get accustomed to.

Cross walking between the two code sets is usually straightforward when the codes have a 1:1 conversion. But in some cases, the conversion is not so easy. A code may have 1 to multiple conversions between the code sets and some have changed terminologies altogether.

You May Also Like…


Submit a Comment

Your email address will not be published. Required fields are marked *

Ready To Get Started?

Pin It on Pinterest