What is ICD-10 code I10?

I10 is the ICD-10-CM diagnosis code for Essential (primary) hypertension. High blood pressure that develops without an identifiable secondary cause, also known as primary hypertension. This is the most common type of high blood pressure. I10 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. I10 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

I10 does not map to a payment HCC under the CMS-HCC V28 or V24 community risk adjustment model, but it does map under the Part D RxHCC model (Hypertension). The CMS-HCC ESRD model applies to beneficiaries with end-stage renal disease, and the Part D RxHCC model drives the prescription-drug (Part D) risk score, so I10 can still affect risk-adjusted payment for those populations even though it carries no V28/V24 community RAF.

Yes. I10 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. I10 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

What is the V28 vs V24 difference for I10?

I10 does not map to a payment HCC under either the CMS-HCC V28 risk adjustment model or the older V24 model. V28 reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition. Because neither community model rewards I10 with a risk adjustment factor, it contributes zero to a Medicare Advantage beneficiary's V28/V24 community RAF score in either version. It does, however, map under the Part D RxHCC model (Hypertension), which affects the ESRD and/or Part D (RxHCC) risk scores. Coders should check whether provider documentation supports a more specific child code that does map to a community payment HCC.

What should coders know when reporting I10?

I10 is used when hypertension is documented without mention of heart disease, kidney disease, or secondary causes Do not use I10 if the hypertension is secondary to another condition; instead use the appropriate I11-I15 code

2026 ICD-10-CM I10: Essential (primary) hypertension

ICD-10-CM Code View

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Code lookupI10Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Diseases of the circulatory system (I00-I99) / Hypertensive diseases (I10-I1A)

I10

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Essential (primary) hypertension

High blood pressure that develops without an identifiable secondary cause, also known as primary hypertension. This is the most common type of high blood pressure.

Buddy Insight

CMS-HCC V28

N/A

—

Not risk-adjusted for this model/period.

Not mapped

CMS-HCC V24

N/A

—

Not risk-adjusted for this model/period.

Not mapped

ACA/HHS

N/A

—

Not risk-adjusted for this model/period.

Not mapped

ESRD/PACE

N/A

—

Not risk-adjusted for this model/period.

Not mapped

RXHCC

Mapped

HCC 187

Hypertension

RAF 0.056

Code Book Path

Official

I1Hypertensive diseases (I10-I1A)

I10Essential (primary) hypertension

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for I10 in this effective period.

Excludes 2

Official

essential (primary) hypertension involving vessels of brain (I60-I69)
essential (primary) hypertension involving vessels of eye (H35.0-)

Related Child Codes

Official

ICD-10-CM does not list child codes under I10 for this display context.

Includes

Official

high blood pressure
hypertension (arterial) (benign) (essential) (malignant) (primary) (systemic)

Excludes 1

Official

hypertensive disease complicating pregnancy, childbirth and the puerperium (O10-O11, O13-O16)

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for I10 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for I10 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for I10 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Provider documentation of hypertension diagnosis (not just an elevated blood pressure reading)

Current blood pressure reading

Assessment of whether hypertension is controlled or uncontrolled

Current antihypertensive medication regimen

MEAT Support

HCC Buddy guidance

Provider documentation of hypertension diagnosis (not just an elevated blood pressure reading)

Current blood pressure reading

Assessment of whether hypertension is controlled or uncontrolled

Current antihypertensive medication regimen

Audit Caution

HCC Buddy guidance

Using I10 when the patient also has heart disease — ICD-10 guidelines assume a causal relationship; use I11.x instead

Using I10 when the patient also has chronic kidney disease — ICD-10 guidelines assume a causal relationship; use I12.x instead

Using I10 when both heart disease and CKD are present — use I13.x combination codes

Coding elevated blood pressure (R03.0) as hypertension without a provider diagnosis

Common Mistakes

HCC Buddy guidance

I11.0 — Hypertensive heart disease with heart failure (use when hypertension and heart failure coexist — per ICD-10 guidelines, a causal relationship is assumed)

I11.9 — Hypertensive heart disease without heart failure (use when hypertension coexists with heart disease)

I12.0 / I12.9 — Hypertensive chronic kidney disease (use when hypertension and CKD coexist — causal relationship is assumed)

I13.x — Hypertensive heart and chronic kidney disease (use when all three conditions coexist)

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is I10 an HCC code?

I10 is not in the CMS-HCC V28 or V24 community payment model, but it does map to Hypertension under the Part D RxHCC model.

Code: I10
Description: Essential (primary) hypertension
HCC (V28): No CMS-HCC V28 mapping
RAF: —
Billable: Yes
Payment year: 2026

HCC Category Mapping

RxHCCHCC 187, Hypertension

0.056

Each model's RAF is its CMS base weight for that model's standard population, so weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.

Work I10 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for I10

For I10 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.

MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
EEvaluate: test results, medication response, or physical findings reviewed by the provider
AAssess: explicit mention in the assessment or plan with acknowledgment of status
TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed I10 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

I10 is the ICD-10-CM diagnosis code for essential (primary) hypertension. High blood pressure that develops without an identifiable secondary cause, also known as primary hypertension. This is the most common type of high blood pressure. I10 sits in the ICD-10-CM chapter for diseases of the circulatory system (i00-i99), within the section covering hypertensive diseases (i10-i1a).

I10 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

This code does not map to a CMS-HCC V28 payment category. Capture depends on documentation that supports the diagnosis; verify the HCC assignment against the current CMS mapping for the applicable payment year. Coders reviewing I10 should check whether additional documentation would support a more specific child code in the same hierarchy that does map to a payment HCC, capturing the correct specificity is the highest-impact RAF improvement available within accurate coding.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for I10 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•I10 is used when hypertension is documented without mention of heart disease, kidney disease, or secondary causes
•Do not use I10 if the hypertension is secondary to another condition; instead use the appropriate I11-I15 code

Clinical Significance

Essential hypertension is one of the most prevalent chronic conditions in the United States, serving as a major risk factor for cardiovascular disease, stroke, chronic kidney disease, and heart failure. While it does not map to a CMS-HCC category, it is a critical comorbidity that influences treatment complexity and is foundational for many combination codes involving hypertensive heart and kidney disease.

Documentation Requirements

✓Provider documentation of hypertension diagnosis (not just an elevated blood pressure reading)
✓Current blood pressure reading
✓Assessment of whether hypertension is controlled or uncontrolled
✓Current antihypertensive medication regimen
✓Evaluation for end-organ damage (cardiac, renal, cerebrovascular)
✓If heart disease or chronic kidney disease is present, document whether the conditions are related to hypertension

Includes

high blood pressure
hypertension (arterial) (benign) (essential) (malignant) (primary) (systemic)

Excludes 1, Do NOT code together

hypertensive disease complicating pregnancy, childbirth and the puerperium (O10-O11, O13-O16)

Excludes 2, Not included here, may code separately

essential (primary) hypertension involving vessels of brain (I60-I69)
essential (primary) hypertension involving vessels of eye (H35.0-)

Commonly Confused Codes

•I11.0: Hypertensive heart disease with heart failure (use when hypertension and heart failure coexist: per ICD-10 guidelines, a causal relationship is assumed)
•I11.9: Hypertensive heart disease without heart failure (use when hypertension coexists with heart disease)
•I12.0 / I12.9: Hypertensive chronic kidney disease (use when hypertension and CKD coexist: causal relationship is assumed)
•I13.x: Hypertensive heart and chronic kidney disease (use when all three conditions coexist)
•I15.x: Secondary hypertension (use when hypertension has an identifiable cause)
•R03.0: Elevated blood pressure reading (use for an incidental finding, not a diagnosis of hypertension)

Code Hierarchy

└I10Essential (primary) hypertension

HCC Buddy Code Card

I10

Is I10 an HCC code?

HCC Category Mapping

MEAT Criteria for I10

Get the V28 RAF + MEAT cheat sheet

What This Code Means

Coding Tips

Clinical Significance

Documentation Requirements

Includes

Excludes 1, Do NOT code together

Excludes 2, Not included here, may code separately

Commonly Confused Codes

Code Hierarchy

More on I10

Referenced in blog posts

In the news

Work I10 in HCC Buddy

I10 ICD-10-CM Code: Essential (primary) hypertension

HCC Buddy Code Card

I10

Is I10 an HCC code?

HCC Category Mapping

MEAT Criteria for I10

Get the V28 RAF + MEAT cheat sheet

What This Code Means

Coding Tips

Clinical Significance

Documentation Requirements

Includes

Excludes 1, Do NOT code together

Excludes 2, Not included here, may code separately

Commonly Confused Codes

Code Hierarchy

More on I10

Referenced in blog posts

In the news

Work I10 in HCC Buddy