Home Health ICD-9/ICD-10 Alert

Tip: Physician documentation is key.

If you incorrectly dig into hypertension ICD-9 codes, you could set your claim up for limbo land. Take this true/false quiz to see if you're really going that necessary extra mile, and read our expert commentary on the answers afterward.

Question 1: The documentation specifies that your patient has hypertension. This is enough information to choose a specific ICD-9 code.

True or false?

Question 2: When the type of hypertension isn't specified, you can assume that means it's benign because that's more common.

True or false?

Question 3: Malignant or benign hypertension is the highest degree of specificity you can get with one hypertension code.

True or false?

Get the Answers

To save time and increase coding accuracy, you must determine if documentation is sufficient enough to point you to a specific hypertension code.

See if you make the grade with these answers.

Answer 1: False.

You have enough information to code hypertension, but you'll have to use an unspecified code, says Trish Twombly, RN, BSN, HCS-D, CHCE, director of coding with Foundation Management Services in Denton, Texas. Try to help physicians in the habit of merely writing "hypertension" on the patient's record to get more specific.

Vital: Remind physicians to tell you explicitly what type of hypertension they're treating. In other words, physicians need to state the details of a patient's hypertension in the medical record.

Action: Explain to the physician that adequate information for medical purposes isn't always adequate for coding purposes. Physicians also need to indicate whether a patient's hypertension is malignant or benign and also define how any other manifestations are related to the hypertension.

Answer 2: False.

When you don't know whether the hypertension is malignant or benign, you should never automatically assume the physician means benign. Coding rules state that only a physician can decide whether hypertension is malignant or benign, Twombly says.

Guidelines specify that hypertension has to be coded as unspecified if the physician doesn't specify benign or malignant.

Rule of thumb: Don't assume when deciding whether to code malignant or benign.

Heads up: The hypertension table in the ICD-9 manual's index lists three possible categories into which hypertension may fall: malignant, benign, and unspecified. The fourth digit of the hypertension code you report will differ depending on which category you choose. For instance, you'll report 401.0 for malignant essential hypertension, 401.1 for benign essential hypertension, and 401.9 for unspecified.

"Do not use either .0 malignant or .1 benign unless medical record documentation supports such a designation," according to the 2009 ICD-9-CM Of-ficial Guidelines for Coding and Reporting.

Common assumption: Because benign hypertension is more common, physicians often assume they are indicating benign hypertension when they simply write "hypertension." But if the documentation doesn't specifically state "benign" or "malignant," the only accurate choice you have is to report an unspecified code -- 401.9 (Essential hypertension; unpecified).

Mistake: When admitting a patient who has returned home from the hospital, don't assume you can list 401.0 just because documentation from the hospital states that the patient had malignant hypertension. The patient may have had malignant hypertension while in the hospital, but it may no longer be malignant once he returns home.

"Malignant hypertension is rare to code in home health," Twombly says. Patients with malignant hypertension have a systolic blood pressure of 120 or greater when they are on their medication, she says. Such patients would most likely be in the ICU.

Answer 3: False.

Identifying whether the hypertension is benign or malignant won't tell the whole story -- this only refers to idiopathic hypertension, the kind of hypertension that occurs without apparent organic cause, Twombly says.

You've also got to show whether the hypertension is primary or secondary to a patient's condition. Most hypertension is considered primary or essential hypertension, coded with a code from the 401 category. Primary hypertension can also be categorized according to end organ involvement: hypertensive heart disease with or without heart failure (402), hypertensive chronic kidney disease (403), or hypertensive heart and chronic kidney disease (404). Secondary hypertension will be documented by the physician as such and should not be coded otherwise.

Impact: You have to discern the manifestations properly to assign the correct code.

Sort Your Primary, Secondary Diagnoses

If the patient's hypertension is primary (also known as "essential hypertension"), meaning that another condition is not causing the hypertension, you need to list the 401.x hypertension code first.

Keep in mind: Patients sometimes have hypertension and chronic kidney disease, and ICD-9-CM assumes a cause-and-effect relationship. In this case, 403.XX (Hypertensive chronic kidney disease) indicates hypertensive chronic kidney disease and includes any conditions coded to 401 and 585.X (Chronic kidney disease [CKD]). The code indicating the stage of the CKD must be added directly underneath the 403 code. Code category 404.XX (Hypertensive heart and chronic kidney disease) indicates hypertensive heart and chronic kidney disease and cannot be coded unless there is documentation of hypertensive heart disease.

Red flag: Kidney conditions reported with codes other than 585 are not considered hypertensive chronic kidney disease and are not coded with a 403 category code.

If the physician documents that the patient has heart disease due to hypertension, he should also indicate whether the disease is with or without heart failure. This distinction will help you select the best code in the 402 or 404 categories. And if the patient has heart failure, remember to assign a separate code to indicate the type of heart failure.

Although you should never assume whether the doctor meant malignant or benign hypertension in his notes, there are some different coding cases when it's OK to assume. For example, if your patient has both chronic kidney disease and hypertension, you can assume the two are linked and assign a code from the 403.xx category, Twombly says. However, you cannot make the same assumption for a patient with hypertension and heart disease. The physician must document the link between these conditions in order for you to list a code from the 402.xx (Hypertensive heart disease) or 404.xx categories.

Don't Overlook Secondary Hypertension

A patient has secondary hypertension if the hypertension is "due to" or caused by another condition. ICD-9 defines secondary hypertension as "high arterial blood pressure due to or with a variety of primary diseases, such as renal disorders, CNS disorders, endocrine, and vascular diseases."

For secondary hypertension, you should sequence the causal condition first and the hypertension second. For example, if a patient has primary aldosteronism that is causing benign hypertension, you might report 255.10 (Primary aldosteronism) followed by 405.19 (Secondary hypertension; benign; other).