The ICD-10-CM code for congestive heart failure is I50.9 (Heart failure, unspecified), a billable code reported when heart failure is documented without specification of type such as systolic, diastolic, or combined.
Primary codes
Billable
Billable
Extension
—
7th character
—
POA exempt
No
Inclusion terms
- Cardiac, heart or myocardial failure NOS
- Congestive heart disease
- Congestive heart failure NOS
Type 2 excludes
- fluid overload unrelated to congestive heart failure (E87.70)
Coding risks
- Assigning when documentation supports a more specific code
Hierarchy
Code comparison
Compare key differences between related codes to select the most specific option.
| Code | Description | Scenario |
|---|---|---|
| I50.9 | Heart failure, unspecified | Heart failure documented without systolic, diastolic, or left ventricular specification in the record. |
| I50.20 | Unspecified systolic (congestive) heart failure | Systolic heart failure documented without acute, chronic, or acute-on-chronic status specified. |
| I50.30 | Unspecified diastolic (congestive) heart failure | Diastolic heart failure documented without acute, chronic, or acute-on-chronic status specified. |
| I50.40 | Unspecified combined systolic (congestive) and diastolic (congestive) heart failure | Patient with both systolic and diastolic heart failure documented, acuity not specified. |
| I50.1 | Left ventricular failure, unspecified | Left ventricular failure documented without specifying systolic, diastolic, or combined dysfunction. |
Select the most specific code supported by the encounter documentation. More specific codes improve reimbursement accuracy and reduce audit risk.
Code ranges
Heart failure
Category covering left, right, systolic, diastolic, combined, and unspecified heart failure with acuity and chronicity subcategories.
Other forms of heart disease
Sub-chapter covering pericardial, endocardial, myocardial, and valvular disease along with dysrhythmias and heart failure syndromes.
Hypertensive heart and kidney disease
Range capturing hypertensive heart disease with or without heart failure and combined hypertensive heart and chronic kidney disease.
Other rheumatic heart diseases
Range for rheumatic myocarditis, mitral insufficiency, and other chronic rheumatic heart disease including rheumatic heart failure.
Diseases of the circulatory system complicating pregnancy
Range identifying circulatory conditions, including heart failure, that complicate pregnancy, childbirth, or the puerperium.
Coding risks
Avoid these common coding issues when reporting Congestive Heart Failure.
Impact
Assigning I50.9 without explicit type may miscode a documented systolic or diastolic failure as unspecified.
Mitigation
Consider querying the provider when type is absent rather than inferring from ejection fraction or medications.
Related codes
Ancillary and co-coding
Codes commonly reported with the primary diagnosis on the same claim.
Z-code variants
Family history, personal history, or screening encounter codes related to this condition.
In pregnancy
Pregnancy-specific O-code adaptations used in place of the primary when the condition occurs during or complicates pregnancy.
Differential codes
Alternative or commonly confused codes to consider when documentation suggests a different condition than the primary diagnosis.
Frequently asked questions
Use I50.9 only when documentation lacks any mention of systolic, diastolic, or combined dysfunction. Query the provider whenever specificity is achievable.
References
Compiled from the following authoritative coding references. Last updated 2026-08-04.