When a patient presents with elevated blood pressure, your documentation and coding should paint a picture of the severity of the patient presentation. Is the patient generally healthy but presenting with a single episode of elevated blood pressure, is the patient chronically ill with hypertension that has affected other organ systems, or is the patient's condition somewhere in between? With today's focus on population health management and documentation to support correct assignment of hierarchical condition categories (HCCs) for risk-adjustment scoring, it is more important than ever that family physicians understand current codes and guidelines. (See “Hypertension in risk adjustment.”)

The patient scenarios presented in this article are intended to illustrate correct coding for elevated blood pressure and hypertensive conditions commonly seen in primary care. They are not intended to reflect advice on the practice of medicine or to indicate that coding would be the same for all patients with similar presentations. Code selection should be based on documentation specific to each unique patient presentation, including clinical findings and documented medical decision-making (e.g., management options affected by comorbidity).

Although documentation and coding for hypertension can be confusing, it essentially comes down to four questions:

1. Is hypertension the diagnosis, or is elevated blood pressure the appropriate diagnosis?

2. If hypertension is the diagnosis, is it primary or secondary?

3. Is there hypertensive urgency or emergency?

4. Does the patient also have heart or kidney disease?

With that framework in mind, let's take a look at some common scenarios.

ELEVATED BLOOD PRESSURE WITHOUT DIAGNOSIS OF HYPERTENSION

To record an episode of elevated blood pressure in a patient who has no formal diagnosis of hypertension or an isolated incidental finding, you should report ICD-10 code R03.0, “Elevated blood-pressure reading, without diagnosis of hypertension.” This code applies to borderline, transient, or white-coat hypertension.

Scenario: Elevated blood pressure. An established patient with no history of hypertension or other chronic illness presents for a preventive evaluation and management (E/M) service. His blood pressure is elevated on the first reading and drops on reevaluation after he sits quietly for five minutes, but is still slightly above normal limits. The patient has no previous elevated reading. You instruct the patient to restrict sodium and monitor blood pressure periodically. Diagnoses for the visit include elevated blood pressure in addition to a routine health examination with abnormal findings.

If you do suspect hypertension you should document it, but do not report a code for suspected hypertension in the out-patient setting, according to ICD-10. Only report codes for what is known at the end of the encounter. For example, if you ruled out suspected hypertension, you could use ICD-10 code Z03.89, “Encounter for observation for other suspected diseases and conditions ruled out.” Note, however, that when this is the primary diagnosis, some insurers will not cover it, and the patient may have to pay out of pocket.

Scenario: Suspected hypertension. A patient without a diagnosis of hypertension has presented on two prior occasions with elevated blood pressure. At the current encounter for an unrelated problem, knee pain, her blood pressure is again elevated after being measured twice, but she states that it is not elevated when she measures it elsewhere. You recommend that the patient self-measure and record blood pressure with two readings one-minute apart taken twice daily, morning and evening, for a 30-day period so that you can determine average systolic and diastolic pressures and assess whether blood pressure management is required. The patient is scheduled to bring in her blood pressure meter for calibration and training by clinical staff. You also treat her knee pain. You document that you spent 15 minutes of the 25-minute visit face-to-face with the patient counseling or coordinating care. Diagnoses for this visit include knee pain and elevated blood pressure/suspected hypertension.

Scenario: Blood pressure meter calibration and training. A patient with suspected hypertension who has been instructed to begin self monitoring returns with her blood pressure monitoring device. A medical assistant who has been trained to calibrate the device against readings obtained with the practice's blood pressure meter determines the patient's device has acceptable accuracy. The patient is trained on use of the blood pressure cuff and demonstrates accurate use.

Scenario: Self monitoring leading to diagnosis. A patient emails a log of results from home readings to your medical assistant at the end of the 30-day period. The medical assistant calculates the average of the diastolic and systolic readings the patient obtained twice daily on 18 days within the 30-day monitoring period, and she documents all of the readings and the average in the patient record. You diagnose hypertension, order medications, and spend 10 minutes on the phone communicating with the patient about the diagnosis and plan of care.

For ambulatory blood-pressure monitoring for 24 hours or longer, you would use codes 93784, 93786, 93788, or 93790.

BLOOD PRESSURE CHECK BY CLINICAL STAFF

Code 99211 is appropriate for blood pressure checks performed by clinical staff on a date when no physician service takes place. The nonphysician service must be in compliance with incident-to policy, when applicable (i.e., it is a continuation of a physician's plan of care, provided by clinical staff of the physician practice, and in compliance with the in-office supervision requirement). Do not report 99211 when a patient requests a blood pressure check not included in the physician's plan of care if the payer follows Medicare's incident-to policy. Additionally, remember that diagnosis coding should be based only on the physician or other qualified health care professional's documentation. That means if elevated blood pressure is the documented reason for the check by clinical staff and the reading is abnormal, a code for hypertension cannot be assigned without appropriate documentation by a physician or other qualified health care professional.

Scenario: Normal blood pressure check. A week after you have seen a patient who had a borderline high blood pressure reading, the patient returns to your office at your request for blood pressure measurement by your clinical staff (e.g., nurse or medical assistant). The patient's blood pressure is within normal limits, so you advise the patient to schedule the next annual wellness visit.

If the blood pressure reading in the above scenario was abnormal and you saw the patient and diagnosed hypertension, you would report a code for the type of hypertension and an appropriate office visit code (99212-99215). If the blood pressure reading was abnormal but you did not diagnose hypertension, you would report ICD-10 code R03.0, “Elevated blood-pressure reading, without diagnosis of hypertension.”

Scenario: Blood pressure check due to inadequate control of hypertension. A patient being treated for primary hyper-tension was not showing adequate control with current medication at her last visit. You added a second medication and advised the patient to return for evaluation of hypertension by clinical staff. A medical assistant measures the patient's blood pressure and documents the patient's denial of symptoms or complaints. After reviewing the medical assistant's documentation, you advise that the patient should continue current management and return in three months for follow-up.

DIAGNOSED HYPERTENSION

ICD-10 guidelines state the assignment of a diagnosis code is based on the physician's diagnostic statement that the condition exists, not based on clinical criteria used to establish the diagnosis. The physician's statement that the patient has a particular condition is sufficient. However, a diagnosis of “high blood pressure” may not be clear. Is the intent to diagnose hypertension or elevated blood pressure without diagnosis of hypertension? If you aren't specific, coders will need to verify the intended diagnosis before assigning the proper code.

If hypertension is the intended diagnosis, the most basic code is I10, “Essential (primary) hypertension.” Use this code for malignant, resistant, and refractory hyper-tension as well, which are not indexed in ICD-10. Secondary hypertension is reported with codes in category I15 (e.g., I15.0, “Renovascular hypertension”) along with a code for the underlying cause. For post-procedural hypertension, report I97.3. And for hypertensive crisis, report a code from category I16 as well as a code for the type of hypertension (e.g., primary or secondary), and make sure your documentation states crisis, emergency, or urgency. If hypertension is documented as accelerated or malignant, codes from I16 should not be assigned, per ICD-10 guidelines.

Even when hypertension is not the focus of the current encounter, if it is relevant to the other conditions, list it in the diagnoses. Documentation of the impact of hypertension on management of other conditions (e.g., contraindications to certain medications) supports code assignment. Likewise, if other conditions, such as diabetes or morbid obesity, are assessed or managed at a visit, it is appropriate to report those codes in addition to the code for hypertension.

Scenario: Hypertension relevant to visit. A patient requests the Medicare initial preventive physical examination (IPPE). The patient was diagnosed with hypertension five years ago. A staff member measures and documents his blood pressure at 128/84 mm Hg. The patient complains of painful knees that prohibit exercise to lose weight. You recommend acetaminophen for the pain rather than ibuprofen, which the patient is currently using, due to ibuprofen's potential to elevate blood pressure. You verify the patient is taking antihypertensive medications as prescribed and does not yet need a refill. You also advise the patient to continue efforts to reduce calories and limit sodium, and you recommend activities that may help alleviate joint pain. Your diagnoses are routine health examination, bilateral knee pain, hypertension currently controlled with two medications, and obesity with body mass index (BMI) of 31. You order screening laboratory tests to assess blood sugar, cholesterol, etc. All required elements of the IPPE are provided and documented.

In the above scenario, if evaluation of the patient's knee pain or status of hypertension resulted in a significant E/M service with separately identifiable documentation of history, examination, and medical decision making, you could report an E/M office visit code (99212-99215) in addition to G0402. The optional HCPCS codes shown are typically reported only if you are participating in a quality measurement initiative that requires code assignment. (See “Hypertension in quality measure reporting.”)

Scenario: Malignant hypertension. A new, 48-year-old patient who is morbidly obese with a BMI of 42 presents to establish care for hypertension and Type 2 diabetes with retinopathy managed with oral medication. The patient has no complaints. The patient's blood pressure is 178/118 mm Hg dropping to 166/98 mm Hg after a period of rest. You note the A1C is 7. You spend 25 minutes of a 35-minute visit face-to-face with the patient discussing medication compliance, diet, and exercise recommendations. You add a second anti-hypertensive medication. You diagnose malignant hypertension in addition to diabetes type 2 with diabetic retinopathy and morbid obesity.

Scenario: Secondary hypertension. An established, 55-year-old female patient returns for test results following evaluation for atherosclerosis of the renal artery due to sudden onset of hypertension. Based on test results, you diagnose renovascular stenosis due to atherosclerosis of the renal artery.

Scenario: Hypertensive emergency. You see an ill-appearing, established male patient. His blood pressure is 260/170 mm Hg. A daughter is present and states the patient seems very confused today, and it appears the patient has not taken medications for at least four days. The patient states he has a pounding headache and feels nauseous. After examination, you diagnose hypertensive emergency and send the patient to the emergency department of the nearest facility by ambulance. Additional diagnoses include change in mental status and unintentional underdosing of antihypertensive medications.

HYPERTENSIVE HEART DISEASE

The ICD-10 guidelines state that a causal relationship between hypertension and heart disease is assumed, and the conditions should be coded as related (even in the absence of documentation explicitly linking them), unless the documentation clearly states the conditions are unrelated. To report hypertensive heart disease, use a code from category I11 (e.g., I11.0, “Hypertensive heart disease with heart failure”) and report a code for the type of heart failure (e.g., I50.32, “Chronic diastolic heart failure”). Reporting the presence of these conditions is appropriate per ICD-10 guidelines: “Code all documented conditions that coexist at the time of the encounter/visit and require or affect patient care treatment or management.” Failure to document them may also affect the bottom line in value-based payment environments.

If the patient's heart disease and hypertension do not have a causal relationship and if the provider has specifically documented a different cause, the heart disease should be reported with a separate code from category I50.- or I51.4-I51.9. An Excludes1 note advises that codes I51.4-I51.9 should not be reported in conjunction with codes in the I11 category.

Scenario: Hypertension with heart failure. You see a patient for a Medicare subsequent annual wellness visit (AWV). You note the status of the patient's chronic diastolic congestive heart failure and hypertension and compliance with the current treatment plan. All elements of the AWV are provided and documented.

Scenario: Hypertension without heart failure. You see an established patient who has hypertension and left ventricular hypertrophy (without diagnosed heart failure). The patient has no new complaints and current medications are maintained.

In the above scenario, you would report code I51.7 (Cardiomegaly) for ventricular hypertrophy in the absence of hypertension or if your documentation specifically stated the conditions were unrelated.

Scenario: Hypertension and heart condition with different cause. You see a patient for follow-up care who was recently hospitalized for cardiac symptoms now diagnosed as Takotsubo syndrome. The patient also has hypertension.

HYPERTENSIVE KIDNEY DISEASE

When both hypertension and chronic kidney disease are diagnosed, a causal relationship is assumed (in the absence of documentation of a different cause) and a combination code for hypertensive chronic kidney disease is reported in lieu of I10, “Essential (primary) hypertension.” A code for the stage of chronic kidney disease is also reported.

Scenario: Hypertension and chronic kidney disease. An established patient presents in the office for follow-up of hypertension and stage 2 chronic kidney disease.

When both diabetes and hypertension are diagnosed in conjunction with chronic kidney disease, assume both diabetes and hypertension contributed to the kidney disease and report combination codes describing each condition (E11.22, “Type 2 diabetes mellitus with diabetic chronic kidney disease,” and I12.9, “Hypertensive chronic kidney disease with stage 1 through stage 4 chronic kidney disease, or unspecified chronic kidney disease”) with the applicable stage of chronic kidney disease (e.g., N18.2, “Chronic kidney disease, stage 2, mild”).

HYPERTENSIVE HEART AND KIDNEY DISEASE

A single code, I13.0, is used to report a combination of hypertensive heart and chronic kidney disease. However, additional codes are necessary to describe the type of heart failure and the stage of chronic kidney disease.

Scenario: Hypertensive heart and kidney disease. An established patient presents in the office for follow-up of chronic systolic left heart failure, diabetes type 2, hypertension, and stage 3 chronic kidney disease.

BUT WAIT, THERE'S MORE

For the hypertension codes discussed in this article, ICD-10 instructs clinicians to report an additional code to identify tobacco use or exposure:

• Exposure to environmental tobacco smoke (Z77.22),

• History of nicotine dependence (Z87.891),

• Occupational exposure to environmental tobacco smoke (Z57.31),

• Nicotine dependence (F17.-),

• Tobacco use (Z72.0).

Additionally, there are other hypertensive conditions in ICD-10 that are beyond the scope of this article:

• Hypertension of the vessels of the eye (H35.0-) or brain (I60-I69),

• Hypertension in pregnancy, childbirth, or the puerperium (O10-O11 and O13-O16),

• Neonatal hypertension (P29.2).

Consult the ICD-10 book for an explanation of these and other codes.

For a quick reference to the most common diagnosis codes for hypertension, see the FPM tool ”Coding Hypertensive Diseases Under ICD-10.”