ICD-10 readiness: Coding congestive heart failure

The code structure and code descriptions for coding heart failure in International Classification of Diseases-9th revision-clinical management (ICD-9-CM) and ICD-10-CM run very parallel.In fact, most of the codes look the same; however, just looking at the similarities in the code descriptions can lead to miscoding and improper assignment of first-listed or secondary codes.

In ICD-10-CM, heart failure codes are listed in category I50, with the exception of rheumatic or newborn cases of congestive heart failure. See the comparison of category I50 in ICD-10-CM to category 428 in ICD-9-CM, which can be found on the accompanying chart.

As the side-by-side comparison shows, most subcategories reflect the same description, which is also true for the final code choices for systolic, diastolic, and combined cases of congestive heart failure as either unspecified, acute, chronic, or acute on chronic. This remains the same between both classification systems, as does a code for heart failure, unspecified. 

The most obvious difference is the presence of a code in ICD-9-CM for reporting “congestive heart failure” that remains otherwise unspecified. This is no longer the case in ICD-10-CM as no such code is provided.

Even though code I50.9 reflects the identical code description as 428.9 in
ICD-9-CM, the particular diagnoses required to be assigned to code I50.9 are now a little different, and it is important to understand those differences for correct reporting and billing.

NEXT PAGE: Code selection

Heart failure, unspecified (I50.9) is how a diagnosis of ‘congestive heart failure’ or ‘congestive heart disease’ that remains otherwise unspecified must be reported in ICD-10-CM, because it is considered included in unspecified heart failure. It follows, therefore, that this is also true for right ventricular failure (secondary to left heart failure), which is now included in I50.9 as well.

Only when a heart condition classified to I50.- has no stated or implied causal relationship to hypertension mentioned in the documentation is the type of heart failure identified with a code from category I50 assigned separately from other causative heart failure codes. 

Otherwise, the specified type of heart failure must be assigned in addition to the appropriate hypertensive heart failure code listed elsewhere in the circulatory system chapter.

Certain coding instructions for correct code assignment and sequencing of heart failure codes remain the same in both systems while other coding instructions in ICD-10-CM are in direct opposition to ICD-9-CM.

The code first instruction to report heart failure due to hypertension, whether the patient presents with hypertensive heart disease or hypertensive heart and chronic kidney disease, remains the same. ICD-9-CM users are familiar with the code choices in categories 402 and 404 requiring the identification of the type of hypertension as either malignant or benign first before the code for hypertensive heart disease or hypertensive heart and chronic kidney disease can be selected with the appropriate fifth digit for “with heart failure.” 

When coding hypertensive cases of heart failure in ICD-10-CM, no determination of malignant or benign needs to be made, nor is any fifth digit assigned to designate the failure. The code choice is simply I11.0 for hypertensive heart disease with heart failure.

When chronic kidney disease is also present, either code I13.0 for hypertensive heart and chronic kidney disease with heart failure and stage 1 through stage 4 chronic kidney disease, or unspecified CKD or code I13.2 for hypertensive heart and chronic kidney disease with heart failure and with stage 5 chronic kidney disease, or end stage renal disease, is assigned first. The code descriptions are completely self-contained.

The remaining code first sequencing instructions for category I50 are quite different from those found in ICD-9-CM. Other types or causes of heart failure must also be sequenced first in ICD-10-CM. This includes cases of heart failure complicating abortion, and ectopic or molar pregnancy; heart failure following surgery, including obstetrical surgery or procedures; as well as rheumatic cases of heart failure. 

All of these conditions for heart failure must be reported together with the specified type of heart failure as left, right, systolic, diastolic, combined, or unspecified. 

In ICD-9-CM, heart failure complicating labor and delivery, abortion, ectopic pregnancy, and molar pregnancy is excluded from category 428, as is all rheumatic heart failure. These conditions cannot be reported together. 

Rheumatic heart failure (congestive), code 398.91, is reported on its own, as is heart failure complicating obstetric cases. These are reported with the appropriate complication code from the pregnancy, childbirth, and puerperium chapter 11.

Conclusion

Although category structure and code descriptions for heart failure in ICD-9-CM and ICD-10-CM are very similar, sometimes even identical, attention to inclusive and exclusive conditions as well as sequencing for types and causative conditions is necessary for correct code selection in ICD-10-CM. A code that reflects unspecified congestive heart failure is no longer provided in ICD-10-CM. 

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