CPR’s “Coding Corner” focuses on coding, compliance and documentation issues relating specifically to physician billing. This month’s tip comes from Peggy Stilley, the Director of ICD-10 Development and Training for AAPC, a training and credentialing association for the business side of health care.   

Hypertension is a common condition treated in most practices. In ICD-9, diagnosis code selection in category 401 is based on the type of hypertension treated: benign, essential, primary, malignant or unspecified. In ICD-10, the diagnosis codes are simplified and the hypertension table is no longer necessary. The concept of controlled and uncontrolled are not a part of the coding choice, although good clinical documentation should include the status of the patient and the type of hypertension being treated. 

Combination codes have been created to report hypertension with associated conditions.

Categories for hypertension include:

• I10 Hypertension (benign, essential, primary)


• I11 Hypertensive heart disease


• I12 Hypertension and chronic kidney disease


• I13 Hypertensive heart and chronic kidney disease

Category I11, hypertension with heart disease, is assigned when a causal relationship is stated or implied in documentation, such as hypertensive heart disease or heart disease due to hypertension. Use a second code to identify the type of heart failure, if present.

Example: A patient is seen for a three-month check-up for hypertensive heart disease. He has no chest pain, no complaints and blood pressure (BP) readings at home are normal. Labs will be drawn and he will follow-up in three months.

• I11.9 Hypertensive heart disease without heart failure

Category I12, hypertension and chronic kidney disease, is assigned for hypertensive chronic kidney disease. The coding guidelines state an assumed relationship when both hypertension and chronic kidney disease (CKD) are documented. A secondary code is needed to identify the stage of CKD.

Example: A patient with malignant hypertension and stage 5 CKD is admitted to the emergency room with elevated BP and edema.

• I12.0 Hypertensive chronic kidney disease with stage 5 chronic kidney disease or end stage renal disease


• N18.5 Chronic kidney disease, stage 5

Category I13, hypertensive heart and chronic kidney disease, is assigned when both hypertensive heart and hypertensive chronic kidney disease are documented in the medical record. The relationship is assumed between hypertension and CKD, but must be implied or stated for hypertension and heart disease. A second code is used to identify the stage of CKD. If heart failure is present, a third code is used to identify the type of heart failure (diastolic, systolic, left ventricular, combined diastolic or systolic).

Example: A patient is admitted with acute diastolic heart failure due to hypertension with end stage renal disease (ESRD).

• I13.2 Hypertensive heart and renal disease with heart failure due to hypertension with end stage renal disease


• I50.31 Acute diastolic (congestive) heart failure


• N18.6 ESRD

When both hypertension and heart disease are stated in documentation, but the causal relationship is not stated or implied, each code is reported separately and the combination code is not used.

Example: A 67-year-old patient is seen for benign hypertension. He continues to smoke two packs of cigarettes per day, and does not want to stop. BP is 165/110. Physician adjusts medications, counsels on smoking. Diagnosis is benign hypertension without good control, nicotine dependence.

• I10 Hypertension (essential, benign, primary)


• F17.210 Dependence, nicotine, cigarette, uncomplicated

Hypertension, whether uncontrolled, untreated or not responding to current medication, is assigned code I10. An instructional note provided for categories I10-I15 states to use an additional code to identify exposure to environmental tobacco smoke (Z77.22), history of tobacco use (Z87.891), occupational exposure to environmental tobacco smoke (Z57.31), tobacco dependence (F17-) or tobacco use (Z72.0).

Example:

Subjective: 75-year-old female is seen for follow up for chronic hypertensive heart disease. She has been having ongoing shortness of breath and orthopnea. Recent EKG demonstrates findings consistent with cardiomegaly, but no recent change since a prior EKG. Currently she is on Lasix, Lanoxin and Atenolol. Social history shows her to be a former smoker.

Objective: BP = 175/95. Heart rate=100. Chest X-ray shows mild pulmonary edema. There is 2+ pitting edema in both ankles.

Assessment: Hypertension – poorly controlled chronic diastolic congestive heart failure

• I11.0 Hypertensive heart disease with heart failure


• I50.32 Chronic diastolic (congestive) heart failure


• Z87.891 History of tobacco use

In this case, hypertensive heart disease is documented with the causal relationship, allowing for combination code I11 to be used. An instructional note at I11.0 states to use an additional code to identify the type of heart failure. In this example, it is chronic (congestive) heart failure. An instructional note provided for categories I10-I15 states to use Z87.891 for history of tobacco use.