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Cardiology Coding:

Here’s What You Need to Know About Heart Failure Coding

Get into the nitty-gritty documentation to find the correct HF code to report.

Heart failure (HF), also sometimes referred to as congestive heart failure (CHF), affects nearly 6.7 million people over the age of 20 in the U.S., according to the Centers for Disease Control and Prevention (CDC) and 2024 and 2019 reports from the American Heart Association, and cost an estimated $30.7 billion in healthcare service and medicine spending and missed days of work.

As a cardiology coder, you will probably see patients with heart failure. Here’s what you need to know to code the condition.

Know the Basics

HF is a condition where the heart is unable to pump blood well enough to supply it to the entire body. This causes fluid to back up in the lungs and lower extremities over time. There are medications and other surgical therapies out there that can be prescribed when needed. Although the heart continues to work, over time it must work harder and harder and still cannot keep up with the supply and demand within the body.

This can also lead to other conditions in the body becoming worse, as well as other conditions that can worsen the HF itself, such as hypertension and chronic kidney disease. These conditions have a causal relationship, which means that they are assumed as related, meaning without definitive documentation stating they are unrelated, they will always be considered related.

Recognize Signs and Symptoms

The most common signs and symptoms of congestive heart failure include shortness of breath; chest pain; swelling in the ankles, legs and abdomen; and heart palpitations. Other factors that can have a cause-and-effect relationship with HF are obesity, diabetes, coronary artery disease, and previous heart attack. We also need to address the complications of HF; these include but are not limited to cardiac arrest, heart valve issues, other organ damage, and pulmonary hypertension.

Happy elderly patient with medical health checkup with cardiologist or geriatric doctor.

There are four stages of HF:

  1. Stage A: This is considered to be pre-heart failure, which means the patient is at a higher risk of heart failure due to family history or other comorbidities.
  2. Stage B: This is a level above stage A pre-heart failure, now progressing to the left ventricle no longer working to the fullest and now considered abnormal with no previous signs/symptoms.
  3. Stage C: This is now considered to be true HF with signs/symptoms, broken down into systolic, diastolic, and combined. Severity is broken down into acute, chronic, and acute on chronic. Treatment is actively pursued.
  4. Stage D: This is also called advanced or end-stage HF and does not get better with treatment.

Become Familiar With Relevant Codes

There are many facets of heart failure, and also many ways to report the conditions.

Two examples:

  • I50.9 (Heart Failure, unspecified), which is used when no additional information is available to code to a higher specificity
  • I50.1 (Left Ventricular Failure, unspecified), also known as left heart failure

Systole is the contraction of any heart chamber. Systolic heart failure is broken down into the following four codes and is also known as reduced ejection fraction (EF) or abbreviated as HFrEF:

  • I50.20 (Unspecified systolic (congestive) heart failure), which is used when only HFrEF is documented
  • I50.21 (Acute systolic (congestive) heart failure)
  • I50.22 (Chronic systolic (congestive) heart failure)
  • I50.23 (Acute on chronic systolic (congestive) heart failure)

Diastole is the relaxation of any heart chamber. Diastolic heart failure is broken down into the following four codes and is also known as preserved EF or abbreviated as HFpEF:

  • I50.30 (Unspecified diastolic (congestive) heart failure), which is used when only HFpEF is documented
  • I50.31 (Acute diastolic (congestive) heart failure)
  • I50.32 (Chronic diastolic (congestive) heart failure)
  • I50.33 (Acute on chronic diastolic (congestive) heart failure)

Combined systolic and diastolic heart failure is also broken down into the following four codes. When billing combined heart failure, you will no longer assign the codes from subcategories I50.2- or I50.3-, because they are encompassed in the combined codes per Excludes1 notes:

  • I50.40 (Unspecified combined systolic and diastolic (congestive) heart failure)
  • I50.41 (Acute combined systolic and diastolic (congestive) heart failure)
  • I50.42 (Chronic combined systolic and diastolic (congestive) heart failure)
  • I50.43 (Acute on chronic combined systolic and diastolic (congestive) heart failure)

Other heart failure codes include:

  • I50.810 (Right heart failure, unspecified)
  • I50.811 (Acute right heart failure)
  • I50.812 (Chronic right heart failure)
  • I50.813 (Acute on chronic right heart failure)
  • I50.814 (Right heart failure due to left heart failure)
  • I50.82 (Biventricular heart failure)
  • I50.83 (High output failure)
  • I50.84 (End stage heart failure)
  • I50.89 (Other heart failure), which is used when additional information is available, but there is no code for a higher specificity

Follow the Guidelines

Coding guidelines for congestive heart failure include order of the diagnosis codes when billed with both hypertension and chronic kidney disease as mentioned above.

Hypertension has combination codes (I11-I13) that must be assigned when related to the congestive heart failure and sequenced based on the reason for the encounter. When billing with chronic kidney disease (N18.1-N18.6), these codes are also sequenced based on the reason for the encounter. Make sure to follow the coding guidelines in the Tabular List for Code also notes with these codes.

As with all other coding, educating the provider that the documentation should meet the highest specificity known at the time of the encounter will allow you to assign the most accurate ICD-10-CM code. This affects multiple areas of coding and is always best practice.

Cristin Robinson, CPC, CPMA, CCC, CRC, CEMC, AAPC Approved Instructor,
Education Coding Consultant, Bristol, Tennessee