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Top outpatient diagnoses by ICD-10 code

Top outpatient diagnoses by ICD-10 code

In recent years, a major shift in where patients prefer to receive care has sent waves across the healthcare industry. According to Definitive Healthcare data, and dozens of studies documenting the trend, more procedures and services that have historically been performed in inpatient care settings are now done in outpatient facilities.

What’s behind the growth in outpatient care?

Several factors have contributed to the rise in outpatient care. Clinical advancements in minimally invasive surgical procedures and new anesthesia techniques reduce complications and accelerate patient recovery. Meanwhile, the expansion of telehealth technology, remote patient monitoring tools, and EMRs are simplifying the patient monitoring process, lessening the need for admissions. This shift in care is helping to lower overall care costs, improve patient outcomes, and reduce unnecessary admissions.

Using ClaimsMx and HospitalView, we ranked the top ten outpatient diagnoses made at hospitals in 2021 by ICD-10 code.

Top 10 outpatient diagnoses in 2021

ICD-10 code 

ICD-10 description 

% total diagnoses 


Essential (primary) hypertension 



Contact with and (suspected) exposure to COVID-19 



Other long term (current) drug therapy 



Hyperlipidemia, unspecified 



Type 2 diabetes mellitus without complications 



Encounter for screening mammogram for malignant neoplasm of breast 



Encounter for immunization 



Chest pain, unspecified 



Gastro-esophageal reflux disease without esophagitis 





Fig. 1: Data from the Definitive Healthcare ClaimsMx product. Claims data is sourced from multiple medical claims clearinghouses in the United States and updated monthly. Data accessed October 2022.

What were the most common outpatient diagnoses in 2021?

Essential (primary) hypertension, commonly known as high blood pressure, ranks number one on our list, accounting for 3.0% of total outpatient diagnoses. Its ICD-10 code is I10.

Unsurprisingly, COVID-related diagnoses were frequently given in 2021. Ranking in second place with 2.5% of total diagnoses was ICD-10 code Z20822—contact with and suspected exposure to COVID-19. And in tenth place is ICD-10 code U071, the diagnosis code for COVID-19, accounting for 0.70% of total diagnoses.

Management of chronic conditions makes up a significant portion of the most commonly reported diagnoses, such as hypertension, chest pain, type 2 diabetes, and long-term drug therapy. Hypertension and type 2 diabetes are both common throughout the U.S., and chest pain is a symptom of various conditions like gastroesophageal reflux disease (ICD-10 code K219), angina, stress, and more.

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Ethan Popowitz

About the Author

Ethan Popowitz

Ethan Popowitz is a Senior Content Writer at Definitive Healthcare. He writes data-driven articles about telehealth, AI, the healthcare staffing shortage, and everything in…

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