I50.9 is the CHF ICD 10 code for congestive heart failure when the diagnosis does not specify a more specific type. If the documentation states chronic systolic, acute diastolic or combined heart failure, for example, a more specific code is warranted.
The hardest part is where the chart may not say everything. For example, CHF may be on the problem list. The assessment, however, may state a different type. Hypertension or kidney disease may also require additional codes and a different sequence.
To find the right family of codes, use the code lists below. See the documentation and instructions to see if the code in question can be coded on the claim.
Three Details Decide Which Code Fits
CHF coding reviews answer three main questions:
- Which type has the provider diagnosed? Look for systolic heart failure, diastolic heart failure, combined heart failure, right ventricular heart failure, or other types of heart failure documented in the record.
- Which acuity does the record support? Identify acute, chronic, and acute on chronic heart failure, following the Alphabetic Index for the documented wording.
- What associated conditions need to be reported? Consider heart failure and related conditions such as hypertension, chronic kidney disease, and other underlying conditions that may affect the code combination required to be reported.
Answering these questions provides better guidance than selecting a code based upon a group of heart failure symptoms. Edema and fatigue can support a clinical judgment, but do not prove type of heart failure.
The same holds true for treatment. Intravenous diuretics do not, by themselves, prove acute heart failure. If a medication is given for the treatment of HFrEF and the documentation states heart failure with reduced ejection fraction (HFrEF), then that code should be reported.
I50.9 Is Appropriate When the Type Remains Unspecified
There is nothing intrinsically incorrect with choosing I50.9. As stated in the Code Crosswalk, it denotes unspecified heart failure and may be assigned when heart failure is documented but no other specification is offered.
Let’s say a provider documented a diagnosis of heart failure and, based on the documentation, the assessor would report no evidence of systolic or diastolic or other specific types of heart failure. In the absence of documentation stating otherwise, I50.9 may be the most accurate code.
However, if an assessor documented heart failure and the type was reported as systolic, then I50.22 would be most accurate. Using I50.9 in that situation would result in a loss of information.
There are two types of documentation gaps that can result in differing codes:
- Type may be missing and acuity is present: “CHF” may support I50.9.
- Acuity may be present and type is missing: “Systolic heart failure” would support the ICD-10 code family I50, and I50.20 would be the most appropriate code for unspecified acuity.
Parallel codes would be I50.30 for diastolic failure and I50.40 for combined failure.
“Acute CHF” does not always mean acute systolic failure. The Index can still point to I50.9, and clarification may help, but coders cannot add or assume a diagnosis.
CHF ICD 10 Code List: The I50 Heart Failure Family
This reference provides examples of codes for which I50 are required. Abbreviations are used for description; HF = heart failure. Confirm the chosen code is correct and verify the instructions for the code set applicable to the encounter.
| Code | Heart failure description | Documentation to look for |
|---|---|---|
| I50.1 | Left ventricular failure, unspecified | Left ventricular failure without a more specific applicable classification |
| I50.20 | Systolic HF, acuity unspecified | Systolic HF or HFrEF without established acuity |
| I50.21 | Acute systolic HF | Acute systolic failure |
| I50.22 | Chronic systolic HF | Chronic systolic failure or chronic HFrEF |
| I50.23 | Acute on chronic systolic HF | Acute worsening of chronic systolic failure or applicable indexed wording |
| I50.30 | Diastolic HF, acuity unspecified | Diastolic HF or HFpEF without established acuity |
| I50.31 | Acute diastolic HF | Acute diastolic failure |
| I50.32 | Chronic diastolic HF | Chronic diastolic failure or chronic HFpEF |
| I50.33 | Acute on chronic diastolic HF | Acute worsening of chronic diastolic failure or applicable indexed wording |
| I50.40 | Combined systolic and diastolic HF, acuity unspecified | Combined failure without established acuity |
| I50.41 | Acute combined systolic and diastolic HF | Acute combined failure |
| I50.42 | Chronic combined systolic and diastolic HF | Chronic combined failure |
| I50.43 | Acute on chronic combined systolic and diastolic HF | Acute worsening of chronic combined failure or applicable indexed wording |
| I50.810 | Right HF, unspecified | Right ventricular failure without further classification |
| I50.811 | Acute right HF | Acute right ventricular failure |
| I50.812 | Chronic right HF | Chronic right ventricular failure |
| I50.813 | Acute on chronic right HF | Acute worsening of chronic right ventricular failure or applicable indexed wording |
| I50.814 | Right HF due to left HF | A documented causal relationship between left and right failure |
| I50.82 | Biventricular HF | Failure involving both ventricles, with attention to whether I50.814 applies |
| I50.83 | High output HF | A provider-established diagnosis of high output failure |
| I50.84 | End stage HF | End stage or Stage D heart failure |
| I50.89 | Other HF | A specified form that the Alphabetic Index directs here |
| I50.9 | HF, unspecified | Heart failure without a more specific documented classification |
You must submit valid, complete code. Characters are not needed for I50.2x, I50.3x, I50.4x, I50.8x, or I50.81x, and will not be accepted. A family label such as “I50.2x” is a claim shorthand, not a claim code.
Match HFrEF, HFpEF, and Combined Failure to the Diagnosis
HFrEF is a Member of the Systolic Family
Systolic heart failure is coded from ICD-10-CM codes I50.20-I50.23. Of these codes, I50.22 is used for chronic HFrEF (heart failure with reduced ejection fraction). If the provider documents chronic HFrEF, I50.22 is assigned, even if the documentation does not include the term “systolic.” HFrEF is an accepted inclusion term, and documentation does not need to include the term “systolic” to assign I50.22.
When chronic care management services are rendered, be sure the care plan and diagnosis list align with the provider’s guidance. A single echocardiogram documenting an EF of 30% does not support a diagnosis of chronic systolic heart failure. If the documentation states there is a reduced ejection fraction and heart failure is not documented, ask for clarification. Do not make the diagnosis of heart failure yourself.
HFpEF is a Member of the Diastolic Family
ICD 10 codes relevant to heart failure of the diastolic family are codes in the range of I50.30 to I50.33. HFpEF, is a part of the diastolic family, as well.
A diagnosis of chronic HFpEF, I50.32, is supported by preserved EF. It is important to note, that impaired filling may be present in heart failure and does not automatically refute a diagnosis of heart failure.
There are some exceptions to this. Diastolic dysfunction documented in an image report does not equal a diagnosis of diastolic heart failure. The coder cannot make an assumption and extend the finding to a broader diagnosis.
A Combination of Both is Elsewhere
ICD 10 codes, I50.40 to I50.43, are relevant to a combination of both systolic and diastolic heart failure. I50.42 pertains to a diagnosis of chronic combined systolic and diastolic heart failure.
This combined category also includes heart failure with reduced EF and diastolic dysfunction. Follow the instruction given for the provider’s diagnosis. Do not create a combined diagnosis by taking a systolic measurement from one report and a diastolic measurement from another.
Separate systolic and diastolic codes should not replace the combined code for the same condition, as the category instructions explain.
Mildly Reduced or Improved EF Deserves Careful Review
HFmrEF and HFimpEF describe clinical EF patterns that need more context than a quick acronym-to-code substitution.
Read the provider’s full assessment, and consult the Index and coding instructions. If the wording does not clearly support a type or acuity, seek clarification. Combined failure should not be automatically assumed.
Similarly, improved EF does not mean HF has resolved and the diagnosis should be changed to HFpEF. Those conclusions should remain in the clinical judgment.
Acuity Depends on Diagnostic Wording, Not Treatment Intensity
Within the systolic, diastolic, and combined families, the final digit follows a useful pattern:
| Ending | Acuity | Systolic example |
|---|---|---|
| 0 | Unspecified | I50.20 |
| 1 | Acute | I50.21 |
| 2 | Chronic | I50.22 |
| 3 | Acute on chronic | I50.23 |
This rule only applies to these families. This is not a general rule for all character positions or all I50 codes.
A code for acute on chronic heart failure captures an acute element that overlays a chronic condition. For systolic failure it is I50.23; for diastolic failure it is I50.33; and for a failure of both compartments it is I50.43.
The documentation doesn’t always use the same phrasing. The Index pathway for heart failure with systolic decompensation directs to I50.23. The pathway for diastolic or preserved-EF entries direct to I50.33, and the pathway for combined failure with decompensation directs to I50.43.
Unspecified decompensated heart failure can also direct to I50.9. The absence of decompensation wording to differentiate a systolic or diastolic type does not indicate that a type is not present.
The best course of action is to analyze the actual Index entry and come to an agreement on conflicting remarks. Using a single precise phrase over and over can lead to unnecessary queries, and coming to an assumption about the level of acuity based on treatment or symptoms can lead to unjustified coding.
Hypertension Can Change the Required Code Combination
A heart failure code may be accurate yet incomplete. Hypertension is the most frequent reason.
The ICD-10-CM “with” convention presumes a relationship between the conditions of hypertension and heart failure, unless the provider documents that they are unrelated. The presence of hypertension is often documented, and while an “/due to hypertension” may not be documented, it is not required to show a relationship.
I11.0 is used to identify Hypertensive Heart Disease with Heart Failure
If the rules of combination are met for the hypertensive cardiovascular, renal, and heart disease codes, and the hypertensive cardiovascular disease code does not apply, code I11.0 and the appropriate I50.xx code.
Consider an assessment documenting hypertension and chronic systolic heart failure, and an unrelated condition statement. The relevant combination would be:
I11.0 + I50.22
I11.0 codes hypertensive heart disease, and I50.22 specifies the type and acuity of heart failure. The hypertensive code comes first, and the associated I50 code comes second, as long as other rules governing the code do not take precedence.
I10 is not to be used to repeat hypertension, as it would be captured by I11.0. The order of these codes does not define the principal diagnosis for all admissions.
CKD Can Move the Case Into I13
When hypertension, heart disease, and chronic kidney disease meet the relevant combination rules, review I13 rather than assigning separate I11 and I12 codes for the same relationship.
| Documented combination with heart failure | Combination code | Additional codes |
|---|---|---|
| CKD stages 1–4 or unspecified CKD | I13.0 | Appropriate I50 code and N18 code for CKD stage |
| CKD stage 5 or end stage renal disease | I13.2 | Appropriate I50 code and N18.5 or N18.6 |
For instance, hypertension, chronic diastolic failure, and CKD stage 3b, support I13.0 + I50.32 + N18.32, assuming the relationships in question are not explicitly excluded.
Keep acute kidney injury separate from CKD in your reasoning. An acute kidney problem does not equate to chronic kidney disease or to a particular stage of CKD.
An Unrelated-Condition Statement Changes the Decision
If the provider states that there is no relation between the patient’s hypertension and heart failure, then do not apply the presumed heart relationship. Report the conditions per the appropriate separate coding rules.
In and of itself, a coexisting cardiomyopathy diagnosis does not state that hypertension is unrelated. Look for the relationship language. If CKD is documented as well, evaluate its relationship to hypertension separately.
The Codebook Notes Matter as Much as the Code Description
Instructions in the Tabular List may be missed during a cursory code search. Check the individual codes and be aware of inherited notes from the parent category.
Excludes1 Helps Prevent Duplicate or Incompatible Reporting
An Excludes1 note means the listed codes should not be reported together. The convention allows an exception for clearly unrelated conditions, so ambiguous relationships may require clarification.
For CHF, the systolic and diastolic families exclude the combined family. Reporting I50.22 and I50.32 with I50.42 for the same combined condition would be duplicative of what the combined code communicates.
The distinction between I50.814 and I50.82 also applies. Right heart failure due to left heart failure is different from right heart failure occurring with, but not because of, left heart failure.
Excludes2 Allows Separate Conditions When Documentation Supports
An Excludes2 note means the excluded condition is outside the definition of that code. The note allows both conditions to be reported if the documentation supports.
Category I50 has Excludes2 notes for cardiac arrest and neonatal cardiac failure. I50.9 has an Excludes2 note for fluid overload that is unrelated to CHF.
The distinction lastly mentioned is important. Congestion caused by heart failure, is, by definition, not Fluid Overload and should not automatically be coded as such. Determine if the chart supports the condition.
“Code First” and “Use Additional Code” are Used Simultaneously
The I50. instructions note situations in which the underlying condition is coded before heart failure. Hypertensive Disease and certain Rheumatic, Post Procedural, and Obstetric conditions are examples.
Completing the description of heart failure requires the addition of ICD-10-CM codes from the I50 chapter. This chapter describes details such as the presence of renal disease and decline (i.e., I13.81). Details about the type and stage of chronic kidney disease are required to complete some of the code combination descriptions.
A sequence of events alone is insufficient to establish a possible complication of a procedure. It is not sufficient to document heart failure post-procedure to consider the procedure as the cause. The relationship must be established through clinical documentation and the application of the relevant Coding and Reporting Guidelines.
Instruction to Code Also Does Not Establish the Order Alone
I50.814 instructs to report the type of left ventricular failure. I50.82 also asks to code the right ventricular failure. I50.84, on the other hand, asks to report the type of left ventricular failure as systolic, diastolic, or a combined type.
An instruction to code also does not establish the order by itself. Finish the code combination, then take into account the circumstances that determine order.
Right Ventricular, Biventricular, and End Stage Failure Need Separate Attention
The codes for right heart failure are I50.810 to I50.814. The documentation must show the level of acuity, where applicable, and distinguish if the condition was caused by left heart failure.
Biventricular failure can describe left heart failure and right heart failure, or it can describe systolic and diastolic failure.
In the case of a documented case of biventricular failure, chronic with systolic failure of the left ventricle, I50.82 and I50.22 would be assigned, following the code-also relation. If there is a causal relationship of failure of the left side of the heart to the right side of the heart, I50.814 would be assigned, along with the left-side failure type.
End stage failure of the heart is coded as I50.84. Stage D of the failure of the heart indicates end stage. EF is usually low in end stage failure, and this can be taken into account when assigning codes. Hospice enrollment does not imply end stage heart failure. It has to be confirmed with the NYHA functional class.
Established high output failure of the heart is coded as I50.83, unless the Index indicates to assign a more specific form of failure. In this case, code I50.89 would be assigned.
“Other” and “unspecified” are not interchangeable.
A Useful Assessment Connects the Diagnosis to the Clinical Picture
Providers don’t need to draft essays to describe codeable events. They need to write the clinical conclusion in a way that enables another person to identify the element being evaluated and managed.
An effective assessment captures:
- Type: Systolic/HFrEF, diastolic/HFpEF, combined, right ventricular, or other specified.
- Acuity: Acute, chronic, acute on chronic, or other appropriate indexed description.
- Relationships: Hypertension, CKD, or other relevant underlying conditions.
- Supporting evidence: Relevant symptoms and/or signs, exam, imaging, EF, and response to therapy.
- Management: Plan to address the condition.
For example, an adequate assessment of a patient with chronic hypertension and chronic systolic heart failure might state:
Chronic HFrEF, compensated. Hypertension addressed in the plan. No acute decompensation identified. Continue current management and plan.
Word the assessment as the clinician has described. Don’t let a default selection in the template create ‘acute’ or ‘end stage’ systolic HF.
Separate Code Assignment From Clinical Validation
Determining code assignment relies on the diagnostic statement provided by the practitioner and applicable rules of reporting. Clinical validation considers whether the evidence supports the diagnosis.
An EF result could provide evidence to support the diagnosis of heart failure; however, there is no general requirement to obtain a repeat EF before assigning a code for a patient with a previously documented heart failure with a systolic dysfunction.
If the assessment, imaging interpretation, and other documents are conflicting, use the appropriate process to clear the resolution. Don’t independently change the assessing provider’s diagnostic statement based on your interpretation of a test.
Ask for Clarification without Suggesting a Preferred Outcome
A useful query explains the document gap and also describes relevant clinical information to assist the practitioner in reaching an independent conclusion.
The Care Setting Changes How Uncertain Diagnoses Are Reported
How “Possible CHF” is documented varies depending on the care setting and the type of claim. Outpatient visits, including emergency department and observation care visits, do not report suspected CHF as confirmed. Documented conditions and any separately reportable symptoms and findings should be reported.
Rules for hospital inpatient facility claims are different. When CHF is documented as “probable,” “suspected,” or “possible” at discharge and the guidelines for uncertain diagnosis of an inpatient care claim are in effect, the CHF may be reported as an established diagnosis. In the Physicians Billing Process for professional claims, when a physician takes care of a hospitalized patient, the rules for outpatient care certainty apply, and the claim is coded for a definitive diagnosis. This is done to prevent an incorrect diagnosis from being reported.
For outpatient diagnostic testing, if a definitive diagnosis is documented in the physician’s final interpretation and that report is available to the coder at the time of coding, the diagnosis may be assigned. The coder should not add associated symptoms, which are already explained by the documented diagnosis. An isolated finding of an ejection fraction of less than 50% does not allow the coder to assign CHF without supporting documentation by the physician.
Three Chart Scenarios That Put the Rules Together
These examples illustrate the reasoning for code choice and do not illustrate every possible diagnosis on a complete claim.
Scenario 1: Admission for Acute on Chronic Systolic Failure
The discharge assessment lists chronic systolic failure and hypertension. There is no CKD and there is no statement to indicate that hypertension and heart failure are unrelated.
The ICD-10-CM code for heart failure is I50.23. The hypertensive relationship requires I11.0 and is placed before the associated I50 code, I11.0, if present, is subject to other applicable encounter instructions.
The habit here is to complete the relationship review after the heart failure subtype has been found. I50.23 is a start, but the code combination is not complete.
Scenario 2: Chronic HFpEF with Hypertension and CKD
The admission assessment identifies chronic heart failure with hypertension and chronic kidney disease.
While the chronic component of chronic failure is assigned I50.9 and the chronic component of chronic kidney disease is assigned I12.1, the ICD-10-CM classification provides little instruction for the coding of chronic heart and hypertensive failure, which is assigned I50.0.
A clinic assessment recognizes chronic HFpEF, hypertension, and CKD stage 3b. Documentation does not rule out applicable relationships.
Codes would be I13.0, I50.32, and N18.32.
I13.0 describes hypertensive heart/kidney disease. I50.32 describes diastolic heart failure, and N18.32 describes CKD stage 3b. I11.0 is used to define kidney disease and captures I13.0, but also misses the heart element of the hypertensive disease process.
Scenario 3: A Reduced EF Without Established Heart Failure
An outpatient record describes shortness of breath and a documented EF of 35%. The assessment states to “evaluate for heart failure.”
I50.22 should not be assigned as the EF is reduced. Report the documented reason for the encounter, any established diagnoses, or findings according to the rules.
The missing element is a supported diagnostic conclusion. More specific coding is unable to close the clinical documentation gap.
A Valid Diagnosis Code Does Not Guarantee Payment
While I50.9 is not a code that is routinely accepted by payers, it may be reportable. The same is true for I50.23.
Coverage depends on the payer. The type of service, its documentation, and the payer’s rules govern the rules for making a claim. ICD-10 describes diagnoses; CPT, and HCPCS, describe services, procedures, and supplies. Just because an individual has a CHF diagnosis, it does not provide automatic coverage for cardiac tests and management services.
Respond differently to a denial based on the actual reason for the denial. A response to a denial for missing authorization should not be the same as a response to a denial for a sequencing error, insufficient service documentation, and/or a diagnosis that does not support the service.
Determine the appropriate code for the documented diagnosis. Assess the claim to confirm it satisfies any additional requirements for a separate service.
Questions That Come Up During CHF Coding
Can I50.9 be used when the provider documents only CHF?
Yes, if the completed documentation establishes heart failure but does not support a more specific type. Check the relevant assessment for available detail and apply any required combination-code instructions. I50.9 should reflect a genuine lack of specificity, rather than replace a subtype the provider has already documented.
Which code distinguishes chronic systolic failure from acute on chronic systolic failure?
Use I50.22 for documented chronic systolic heart failure and I50.23 for acute on chronic systolic heart failure. Follow the provider’s wording through the Alphabetic Index, including applicable decompensation entries. Symptoms, a hospital admission, or medication administration alone do not establish the difference.
Is chronic HFpEF coded as I50.32?
Yes. HFpEF is included in the diastolic heart failure family, and a documented chronic HFpEF diagnosis supports I50.32. Confirm that the record identifies chronic disease rather than an acute or acute-on-chronic episode. A preserved EF measurement without a heart failure diagnosis does not independently support the code.
Should I11.0 and an I50 code appear together?
They generally belong together when hypertension and heart failure meet the presumed-relationship rules and a qualifying I13 combination does not apply. I11.0 represents hypertensive heart disease with heart failure; the I50 code identifies the heart failure detail. A clear unrelated-condition statement changes that assessment.
Can systolic and diastolic codes be billed separately for combined failure?
Separate systolic and diastolic codes should not represent the same documented combined condition. Select the appropriate I50.4-family code, such as I50.42 for chronic combined failure. Check the Excludes1 instructions and assess any other independently reportable diagnoses or required additional codes separately.
Does a low ejection fraction prove that I50.22 applies?
No. I50.22 describes chronic systolic heart failure, not simply a low EF result. The documentation must establish a reportable diagnosis supporting that code. An EF finding can support clinical assessment or clarification, but it does not allow the coder to independently diagnose heart failure or its acuity.
A Practical Check Before You Submit
These are a few practical checks you should do before publishing a claim containing a diagnosis of CHF.
- Can you confirm heart failure is documented according to the rules for this care setting?
- Does the code captured describe the type and acuity of heart failure documented?
- Have you considered hypertension and CKD?
- What about relevant other relationships?
- Are all relevant additional codes, in the correct sequence, captured?
- Have the Tabular instructions, inherited by the code, been reviewed?
- Does the diagnosis list support the clinical judgment?
If you are unclear about any of the above, identify the gap, and take the appropriate review or query to resolve it. Keep this checklist along with your coding reference, so that selecting a code for CHF becomes a deliberate, defendable decision.
Coding references:
CDC ICD-10-CM files
AAPC I50 code family
