The ICD-10 code for hypertension (HTN) is used to document and report elevated blood pressure conditions in clinical settings. Accurate hypertension coding is essential for medical billing, risk adjustment, chronic disease management, quality reporting, and payer compliance.
Hypertension is one of the most commonly diagnosed conditions in healthcare, making correct ICD-10-CM code selection especially important.
ICD Code Description
Primary ICD-10-CM Code: I10
Diagnosis: Essential (primary) hypertension
I10 is used when a patient has chronic high blood pressure with no documented secondary cause. This is the most frequently reported hypertension diagnosis in outpatient and inpatient care.
Clinical Specificity
- Type: Primary (essential) hypertension
- Acuity: Chronic
- Severity: Not specified in ICD-10-CM
- Laterality: Not applicable
- Status: Active condition
Note: ICD-10-CM does not classify hypertension by stage (Stage 1, Stage 2) for coding purposes.
Category & Code Type
ICD-10-CM Chapter
-
Chapter 9: Diseases of the Circulatory System (I00–I99)
ICD-10 Category
-
I10–I16 – Hypertensive diseases
Code Type
- I10 is a billable and specific ICD-10-CM code
- Valid for reimbursement across all care settings
Includes / Excludes Notes
Includes:
- High blood pressure
- Primary hypertension
- Essential hypertension
Excludes:
- Hypertensive heart disease (I11.-)
- Hypertensive chronic kidney disease (I12.-)
- Hypertensive heart and CKD (I13.-)
- Secondary hypertension (I15.-)
- Gestational hypertension (O13.-)
Use combination codes when hypertension is linked to heart or kidney disease.
Coding Guidelines
Key ICD-10-CM rules for hypertension include:
- I10 is used for most uncomplicated hypertension cases
- Hypertension is coded separately unless a combination code applies
- Do not code elevated blood pressure readings alone without a diagnosis
- Use additional codes to identify associated conditions when required
- Hypertension is considered chronic, even if controlled by medication
Billing Considerations
Reimbursement Impact
- Supports billing for evaluation and management (E/M) services, chronic care management, and preventive care
- Affects risk adjustment, HCCs (in certain models), and quality metrics
Payer Considerations
- Payers expect hypertension to be actively managed
- Documentation should support medical necessity for ongoing treatment
- Controlled hypertension should still be coded if treatment continues
Documentation Tips
To support accurate hypertension coding, providers should document:
- Clear diagnosis of hypertension
- Type (primary vs. secondary, if known)
- Current treatment plan (medications, lifestyle counseling)
- Blood pressure trends over time
- Associated conditions (heart disease, CKD, diabetes)
Avoid relying solely on single elevated BP readings without a formal diagnosis.
Common Clinical Examples
- Primary care visit for chronic high blood pressure managed with medication
- Annual wellness exam documenting controlled hypertension
- Follow-up visit for blood pressure monitoring and medication adjustment
- Hospital admission where hypertension is a secondary diagnosis affecting care
Common Errors & Denials
Frequent coding mistakes include:
- Coding hypertension based only on elevated readings
- Missing combination codes for heart or kidney involvement
- Failing to code controlled hypertension
- Using unspecified circulatory codes instead of I10
These errors can lead to claim denials or inaccurate risk reporting.
Key Takeaways
- I10 is the primary ICD-10-CM code for essential hypertension
- It is a billable diagnosis code used across all care settings
- Hypertension is considered chronic, even when controlled
- Use combination codes when heart or kidney disease is present
- Clear documentation supports accurate coding and reimbursement
FAQ:
What is the ICD-10 code for hypertension?
The most common ICD-10-CM code for hypertension is I10.
Is I10 a billable diagnosis code?
Yes, I10 is billable and valid for reimbursement.
Can hypertension be coded if it is controlled?
Yes. Controlled hypertension should still be coded if the patient remains on treatment.
What if hypertension is caused by another condition?
Use secondary hypertension codes (I15.-) and code the underlying cause if documented.
Does ICD-10 code hypertension by stage?
No. ICD-10-CM does not differentiate hypertension by stages (Stage 1 or Stage 2).
