ICD-10: Coding for Hypertension and Heart Disease

Betsy Nicoletti, MS


August 25, 2015

Keys to the Right Diagnosis Coding

Diagnosis coding is the forgotten stepchild in medical practices.

Physician coding has focused on Current Procedural Terminology codes, which drives revenue when services are provided under a fee-for-service model. Diagnosis coding, in contrast, establishes the medical necessity for the service, and can be the reason a claim is denied, particularly for diagnostic tests and other services with payer coverage policies. However, as payment for healthcare services morphs into payment based on utilization, quality, and outcomes, accurately reporting the severity of a patient's conditions is important for physician practices.

Coding for hypertension, hypertensive heart disease, and hypertensive chronic kidney disease hasn't changed much from the ninth edition of the International Classification of Diseases (ICD-9) to the tenth edition (ICD-10). However, too few physicians select the more specific, risk-adjusted codes in ICD-9. The change to ICD-10 provides the opportunity to more accurately report these conditions. The most specific codes in ICD-10 enable a physician communicate the severity of the patient's condition to the payer.

Essential hypertension in ICD-10 has only one code: I10. Coders joke that it is the one code they can easily memorize, because a complete ICD-10 code can be up to seven characters long and is alphanumeric. Both 401.1 (benign hypertension) and 401.9 (hypertension, not otherwise specified) will be replaced by I10—essential (primary) hypertension.

But there are specific codes to describe hypertensive heart disease, hypertensive chronic kidney disease, and hypertensive heart and chronic kidney disease. If a physician determines that a patient has hypertension and heart disease caused by the hypertension, list first the combination code for hypertensive heart disease, either with or without heart failure. If the patient has heart failure, there is a notation to use an additional code from the I50 category to identify the type of heart failure.

A patient with hypertension and chronic kidney disease is coded with a code from category I12, hypertensive chronic kidney disease. I12.0 is for hypertensive chronic kidney disease in a patient with stage 5 or end-stage renal disease or 112.9 for hypertensive chronic kidney disease, stage 1 through stage 4.


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