Hypertension ICD-10 Codes 2026: Complete I10-I16 Reference Guide
The definitive reference for hypertension ICD-10-CM coding. Covers essential hypertension (I10), hypertensive heart disease (I11), hypertensive chronic kidney disease (I12-I13), secondary hypertension (I15), hypertensive crisis (I16), and pulmonary hypertension (I27) with documentation rules, causal relationship guidelines, and coding decision trees.
In This Guide
Hypertension ICD-10 Code Categories
Hypertension codes in ICD-10-CM span categories I10 through I16 in Chapter 9: Diseases of the Circulatory System (I00-I99). Pulmonary hypertension codes are separately classified under I27. According to the CDC, nearly half of American adults have hypertension, making these among the most frequently reported ICD-10 codes in clinical practice.
Essential (Primary) Hypertension
High blood pressure without a documented secondary cause, heart disease, or CKD
Hypertensive Heart Disease
Hypertension with coexisting heart disease (assumed causal relationship)
Hypertensive CKD
Hypertension with coexisting chronic kidney disease (assumed causal)
Hypertensive Heart and CKD
Hypertension with both heart disease and chronic kidney disease
Secondary Hypertension
Hypertension due to an identifiable underlying condition
Hypertensive Crisis
Severely elevated blood pressure with or without end-organ damage
Pulmonary Hypertension
Elevated pulmonary arterial pressure (separate classification)
Essential Hypertension (I10)
I10 — Essential (primary) hypertension is the most commonly reported hypertension ICD-10 code. It is used when a patient has high blood pressure without a documented secondary cause. According to the American Heart Association, essential hypertension accounts for approximately 90-95% of all hypertension diagnoses.
Code I10: What It Includes
- Essential hypertension (primary hypertension)
- Benign hypertension (previously ICD-9 code 401.1)
- Malignant hypertension (previously ICD-9 code 401.0)
- Systemic hypertension NOS
- Hypertension (arterial) (systemic) NOS
Code I10: What It Excludes
- Excludes1: Hypertensive disease complicating pregnancy, childbirth, and the puerperium (O10-O11, O13-O16)
- Excludes2: Essential hypertension involving vessels of brain (I60-I69)
- Excludes2: Essential hypertension involving vessels of eye (H35.0-)
- Excludes2: Neonatal hypertension (P29.2)
- Excludes2: Pulmonary hypertension (I27.0, I27.2-)
When to Use I10
Patient with elevated blood pressure on medication
Whether controlled or uncontrolled, use I10 for essential HTN. ICD-10-CM does not distinguish between controlled and uncontrolled hypertension.
Newly diagnosed hypertension without secondary cause
First encounter for elevated BP meeting diagnostic criteria. No identified underlying etiology.
Do NOT use I10 when heart disease or CKD is present
If the patient has both HTN and heart disease, use I11. If HTN with CKD, use I12. If both, use I13. ICD-10 guidelines assume a causal relationship.
Do NOT use I10 for elevated blood pressure reading without diagnosis
An isolated elevated BP reading is coded R03.0 (Elevated blood pressure reading, without diagnosis of hypertension), not I10.
Important: Controlled vs. Uncontrolled
ICD-10-CM does not differentiate between controlled and uncontrolled hypertension. Both are assigned code I10. However, proper clinical documentation should indicate whether the patient's hypertension is controlled or uncontrolled, as this information is critical for treatment planning, quality measures, and care coordination — even though it does not change the assigned ICD-10 code.
Hypertensive Heart Disease (I11)
Category I11 is used when a patient has both hypertension and heart disease. A key ICD-10-CM coding guideline is the “assumed causal relationship” rule: when hypertension and certain heart conditions coexist, the coder should assume a causal relationship and assign an I11 code — unless the provider explicitly documents that the heart disease is unrelated to hypertension.
Assumed Causal Relationship Rule
Per ICD-10-CM Official Guidelines Section I.C.9.a.1: The classification presumes a causal relationship between hypertension and heart involvement. Use I11 codes for any patient with both hypertension and heart conditions classified to I50.- or I51.4-I51.9, unless the documentation states the conditions are unrelated.
| Code | Description | Additional Codes |
|---|---|---|
| I11.0 | Hypertensive heart disease with heart failure | Must also code I50.- to identify type of heart failure |
| I11.9 | Hypertensive heart disease without heart failure | Includes hypertensive cardiomegaly, cardiomyopathy, cardiovascular disease |
Heart Failure Type Codes (Use with I11.0)
When assigning I11.0, an additional code from the I50.- category must be used to specify the type of heart failure:
Hypertensive Chronic Kidney Disease (I12)
Category I12 is used when a patient has both hypertension and chronic kidney disease (CKD). Similar to hypertensive heart disease, ICD-10-CM guidelines establish an assumed causal relationship between hypertension and CKD — the conditions are presumed to be related unless the provider documents otherwise.
| Code | Description | CKD Stage |
|---|---|---|
| I12.0 | Hypertensive CKD with stage 5 CKD or ESRD | Use additional code N18.5 or N18.6 |
| I12.9 | Hypertensive CKD with stage 1-4 CKD or unspecified | Use additional code N18.1-N18.4 or N18.9 |
Required Additional CKD Stage Codes
An additional code from N18.- must always be assigned with I12 codes to identify the stage of chronic kidney disease:
Assumed Causal Relationship for CKD
Per ICD-10-CM Official Guidelines Section I.C.9.a.2: The classification presumes a causal relationship between hypertension and chronic kidney disease. Assign codes from category I12 when both hypertension and a condition classifiable to N18.- are present. Use I12 codes regardless of which condition is listed as the “reason for encounter” — unless the provider documents the CKD is not due to hypertension.
Hypertensive Heart and Chronic Kidney Disease (I13)
Category I13 is assigned when a patient has hypertension with both heart disease and chronic kidney disease. These combination codes capture the full clinical picture. When all three conditions coexist, use I13 rather than separate I11 and I12 codes.
| Code | Description | Additional Codes |
|---|---|---|
| I13.0 | Hypertensive heart and CKD with heart failure and stage 1-4 CKD or unspecified CKD | Code also I50.- and N18.1-N18.4 or N18.9 |
| I13.10 | Hypertensive heart and CKD without heart failure, with stage 1-4 CKD or unspecified CKD | Code also N18.1-N18.4 or N18.9 |
| I13.11 | Hypertensive heart and CKD without heart failure, with stage 5 CKD or ESRD | Code also N18.5 or N18.6 |
| I13.2 | Hypertensive heart and CKD with heart failure and stage 5 CKD or ESRD | Code also I50.- and N18.5 or N18.6 |
Coding Example: HTN + Heart Failure + CKD Stage 3
A patient presents with hypertension, chronic systolic heart failure, and CKD stage 3a. The correct coding sequence would be:
- I13.0 — Hypertensive heart and CKD with heart failure and stage 1-4 CKD
- I50.22 — Chronic systolic (congestive) heart failure
- N18.31 — CKD, stage 3a
Secondary Hypertension (I15)
Secondary hypertension results from an identifiable underlying condition. Unlike essential hypertension (I10), secondary hypertension has a known cause. Per CMS coding guidelines, two codes are required: one for the underlying condition (sequenced first) and the I15 code for secondary hypertension.
| Code | Description | Common Causes |
|---|---|---|
| I15.0 | Renovascular hypertension | Renal artery stenosis, fibromuscular dysplasia |
| I15.1 | Hypertension secondary to other renal disorders | Polycystic kidney disease, renal parenchymal disease |
| I15.2 | Hypertension secondary to endocrine disorders | Cushing syndrome, pheochromocytoma, primary aldosteronism, thyroid disorders |
| I15.8 | Other secondary hypertension | Coarctation of aorta, drug-induced, sleep apnea-related |
| I15.9 | Secondary hypertension, unspecified | Known secondary cause but not further specified |
Two-Code Requirement
Secondary hypertension requires two codes: one for the underlying etiology and one from category I15. The sequencing depends on the reason for the encounter:
- If the encounter is for the hypertension itself, sequence the I15 code first, followed by the underlying condition.
- If the encounter is for the underlying condition, sequence that condition first, followed by the I15 code.
- If the patient also has secondary hypertension with heart disease or CKD, additional codes from I11-I13 are not used — the I15 category takes precedence for the secondary cause.
Hypertensive Crisis (I16)
Category I16 captures hypertensive crisis — a severe, acute elevation in blood pressure that may or may not involve acute end-organ damage. These codes are used in addition to the underlying hypertension code (such as I10 for essential hypertension). Proper distinction between urgency and emergency is critical for accurate coding and appropriate reimbursement.
| Code | Description | Clinical Criteria |
|---|---|---|
| I16.0 | Hypertensive urgency | Severely elevated BP (typically >180/120 mmHg) without evidence of acute end-organ damage |
| I16.1 | Hypertensive emergency | Severely elevated BP with evidence of acute end-organ damage (brain, heart, kidneys, eyes) |
| I16.9 | Hypertensive crisis, unspecified | Crisis documented but urgency vs. emergency not specified |
Hypertensive Urgency
Severely elevated BP without acute target-organ damage:
- - BP typically >180/120 mmHg
- - Severe headache, anxiety, epistaxis
- - No signs of acute end-organ damage
- - Usually managed with oral medications
- - Gradual BP reduction over 24-48 hours
Hypertensive Emergency
Severely elevated BP with acute target-organ damage:
- - Hypertensive encephalopathy
- - Acute MI or unstable angina
- - Acute pulmonary edema
- - Eclampsia
- - Acute renal failure
- - Requires IV antihypertensives
Coding Note
Code I16 should be used as an additional code with the underlying hypertension code. For example, a patient with essential hypertension presenting with hypertensive emergency would be coded with both I10 and I16.1. Also assign codes for any end-organ damage present, such as acute kidney injury (N17.-), acute MI (I21.-), or hypertensive encephalopathy (I67.4).
Pulmonary Hypertension (I27)
Pulmonary hypertension is classified separately from systemic hypertension in ICD-10-CM. It falls under category I27 (Other pulmonary heart diseases) rather than the I10-I16 hypertension block. Pulmonary hypertension involves elevated pressure in the pulmonary arteries and has distinct pathophysiology and treatment approaches.
| Code | Description |
|---|---|
| I27.0 | Primary pulmonary hypertension (idiopathic PAH) |
| I27.20 | Pulmonary hypertension, unspecified |
| I27.21 | Secondary pulmonary arterial hypertension |
| I27.22 | Pulmonary hypertension due to left heart disease |
| I27.23 | Pulmonary hypertension due to lung diseases and hypoxia |
| I27.24 | Chronic thromboembolic pulmonary hypertension (CTEPH) |
| I27.29 | Other secondary pulmonary hypertension |
| I27.81 | Cor pulmonale (chronic) |
| I27.89 | Other specified pulmonary heart diseases |
Key Distinction
Pulmonary hypertension (I27) is entirely separate from systemic hypertension (I10-I16). A patient can have both conditions simultaneously. If a patient has essential hypertension and pulmonary hypertension, code both I10 and the appropriate I27 code. Do not confuse the two — they represent different disease processes affecting different vascular systems.
Documentation Tips for Accurate Hypertension Coding
Accurate ICD-10 coding for hypertension depends on thorough, specific clinical documentation. The following elements should be consistently captured in the medical record to support proper code assignment, avoid claim denials, and ensure clinical documentation integrity.
Type of Hypertension
Specify whether hypertension is essential (primary), secondary (with cause), or pulmonary. If secondary, document the underlying etiology clearly. Avoid vague terms like “high blood pressure” without a formal diagnosis.
Causal Relationships
Document whether coexisting heart disease and/or CKD are caused by hypertension. If the conditions are unrelated, explicitly state this in the documentation (e.g., “Heart failure is not due to hypertension”). Silence triggers the assumed causal relationship rule.
Heart Failure Type
When heart failure is present, specify: systolic (HFrEF), diastolic (HFpEF), combined, or unspecified. Also document acuity: acute, chronic, or acute-on-chronic. This determines the specific I50.- code required as an additional diagnosis.
CKD Stage
Always document the CKD stage (1-5) or ESRD status. Include GFR values, dialysis status, and any transplant history. The CKD stage determines whether I12.0 or I12.9 (or the corresponding I13 code) is assigned.
Control Status
Document whether hypertension is controlled or uncontrolled. While ICD-10-CM uses the same code (I10) for both, this documentation supports quality measures (HEDIS, MIPS), care planning, and medication management decisions.
Medications
List current antihypertensive medications, dosages, adherence, and any recent changes. Document medication classes (ACE inhibitors, ARBs, calcium channel blockers, diuretics, beta-blockers) and combinations for treatment complexity assessment.
Hypertension Coding Quick Reference
Use this decision tree to quickly determine the correct hypertension ICD-10 code based on the documented clinical scenario. This reference follows the official ICD-10-CM coding guidelines and assumed causal relationship rules.
Essential/primary hypertension. No additional codes required.
I11.0 with HF (+ I50.-) or I11.9 without HF. Assumed causal relationship.
I12.0 (stage 5/ESRD) or I12.9 (stage 1-4) + N18.- code. Assumed causal relationship.
I13.0/I13.10/I13.11/I13.2 based on HF and CKD stage. Additional I50.- and N18.- codes.
Code underlying condition + I15.- code. Sequence depends on reason for encounter.
I16.0 (urgency), I16.1 (emergency), I16.9 (unspecified). Assign with underlying HTN code.
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Frequently Asked Questions
What is the ICD-10 code for hypertension?
The primary ICD-10 code for hypertension is I10 (Essential/primary hypertension). This is the most commonly used hypertension code and includes benign hypertension, malignant hypertension, and systemic hypertension NOS. I10 is a billable code used when a patient has high blood pressure without documented heart disease, chronic kidney disease, or a secondary cause.
What is the difference between I10 and I11?
I10 is for essential (primary) hypertension without heart disease, while I11 is for hypertensive heart disease. ICD-10 coding guidelines establish an assumed causal relationship between hypertension and heart disease when both conditions coexist. If a patient has both hypertension and any form of heart disease (such as cardiomegaly, cardiomyopathy, or heart failure), code I11.0 or I11.9 should be used instead of I10, unless the provider documents the conditions are unrelated.
How do you code hypertension with CKD?
When hypertension and chronic kidney disease (CKD) coexist, use I12 codes. ICD-10 assumes a causal relationship between the two conditions. Use I12.9 for hypertensive CKD with stage 1 through 4 or unspecified CKD, and I12.0 for hypertensive CKD with stage 5 or end-stage renal disease (ESRD). An additional code from N18.1-N18.6 or N18.9 must be assigned to identify the CKD stage.
What is hypertensive crisis ICD-10?
Hypertensive crisis codes are in the I16 category. I16.0 is for hypertensive urgency (severely elevated BP without acute end-organ damage), I16.1 is for hypertensive emergency (severely elevated BP with acute end-organ damage), and I16.9 is for hypertensive crisis, unspecified. These codes should be assigned in addition to the underlying hypertension code (such as I10 for essential HTN).
Does I10 include benign and malignant hypertension?
Yes. ICD-10 code I10 includes benign hypertension, malignant hypertension, and systemic hypertension NOS. Unlike ICD-9, which had separate codes for benign (401.1) and malignant (401.0) hypertension, ICD-10 consolidates these under the single code I10. There is no need to separately specify benign or malignant type in ICD-10-CM.
How do you code hypertension with heart failure?
When a patient has both hypertension and heart failure, use I11.0 (Hypertensive heart disease with heart failure). An additional code from I50.- must also be assigned to specify the type of heart failure (I50.1 for left ventricular failure, I50.20-I50.23 for systolic/HFrEF, I50.30-I50.33 for diastolic/HFpEF, I50.40-I50.43 for combined, or I50.9 for unspecified). ICD-10 guidelines assume a causal relationship between hypertension and heart failure.
What is secondary hypertension ICD-10?
Secondary hypertension uses I15 codes. I15.0 is for renovascular hypertension, I15.1 for hypertension secondary to other renal disorders, I15.2 for hypertension secondary to endocrine disorders, I15.8 for other secondary hypertension, and I15.9 for secondary hypertension unspecified. Two codes are required: one for the underlying condition and the I15 code. The underlying condition is typically sequenced first.
Do you code hypertension as controlled or uncontrolled?
ICD-10-CM does not have separate codes for controlled versus uncontrolled hypertension. Both controlled and uncontrolled essential hypertension are coded to I10. The documentation should note whether hypertension is controlled or uncontrolled for clinical purposes, but the ICD-10 code remains the same. "Uncontrolled" hypertension refers to HTN that has not responded to therapy, while "controlled" means the condition is managed to target levels.
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