What is ICD-10 code I16.1?

I16.1 is the ICD-10-CM diagnosis code for Hypertensive emergency. A life-threatening spike in blood pressure with evidence of acute organ damage, such as stroke, heart attack, or kidney failure. It belongs to the ICD-10-CM chapter for diseases of the circulatory system (i00-i99). I16.1 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. I16.1 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.

Yes. I16.1 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. I16.1 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 I16.1?

I16.1 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 model rewards I16.1 with a risk adjustment factor, it contributes zero to a Medicare Advantage beneficiary's RAF score in either version. Coders should check whether provider documentation supports a more specific child code that does map to a payment HCC.

What should coders know when reporting I16.1?

Always code the associated end-organ damage (e.g., acute coronary syndrome, acute kidney injury) as additional diagnoses This code indicates a true medical emergency requiring immediate intervention

I16.1 ICD-10 Code: Hypertensive emergency

ICD-10-CM Code View

HCC Buddy Code Card

Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

Code lookupI16.1Effective periodFY2026 Apr Update (Apr 1-Sep 30)

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

I16.1

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

Hypertensive emergency

A life-threatening spike in blood pressure with evidence of acute organ damage, such as stroke, heart attack, or kidney failure.

Buddy Insight

CMS-HCC V28

Not risk-adjusted for this model/period.

RAF 0

CMS-HCC V24

Not risk-adjusted for this model/period.

RAF 0

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Not risk-adjusted for this model/period.

RAF 0

RXHCC

Mapped

HCC 187

Hypertension

RAF 0.0

Code Trumping

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Compare selected patient codes to show trumped or trumps impact.

Code Book Path

Official

I16Hypertensive crisis

I16.1Hypertensive emergency

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for I16.1 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for I16.1 in this effective period.

Related Child Codes

Official

I16.0Hypertensive urgency

I16.9Hypertensive crisis, unspecified

Includes

Official

ICD-10-CM does not list Includes notes for I16.1 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for I16.1 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for I16.1 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for I16.1 in this effective period.

Code Also

Official

, if applicable, to identify specific organ dysfunction, such as:
acute kidney injury (N17.-)
acute myocardial infarction (I21.-)
acute pulmonary edema (left and/or right ventricular failure) (J81.0, I50.-)
aortic dissection (I71.0-)

Buddy Documentation Tip

HCC Buddy guidance

Severely elevated blood pressure reading documented

Provider diagnosis of hypertensive emergency

Documentation of acute target organ damage — specify which organ(s) are affected

Type of organ damage: encephalopathy, acute HF, acute MI, acute renal failure, retinopathy, aortic dissection, etc.

MEAT Support

HCC Buddy guidance

Severely elevated blood pressure reading documented

Provider diagnosis of hypertensive emergency

Documentation of acute target organ damage — specify which organ(s) are affected

Type of organ damage: encephalopathy, acute HF, acute MI, acute renal failure, retinopathy, aortic dissection, etc.

Audit Caution

HCC Buddy guidance

Coding as hypertensive urgency (I16.0) when acute organ damage IS present — this is an emergency

Not coding the specific organ damage in addition to the hypertensive emergency code

Failing to distinguish between chronic end-organ damage from longstanding hypertension and ACUTE damage from the current emergency

Using unspecified hypertensive crisis (I16.9) when the record clearly documents organ damage (making it an emergency)

Common Mistakes

HCC Buddy guidance

I16.0 — Hypertensive urgency (use when severely elevated BP is present WITHOUT organ damage)

I16.9 — Hypertensive crisis, unspecified (use only when urgency vs. emergency cannot be distinguished)

I67.4 — Hypertensive encephalopathy (specific type of organ damage that should be coded in addition to I16.1)

I10 — Essential hypertension (underlying condition; I16.1 is the acute event)

Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.

Is I16.1 an HCC code?

No. I16.1 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.

HCC Category Mapping

RxHCCHCC 187, Hypertension

0.000

RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. 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.

MEAT Criteria for I16.1

For I16.1to 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 I16.1 during that encounter, not just copy-forwarded from a problem list.

What This Code Means

I16.1 is the ICD-10-CM diagnosis code for hypertensive emergency. A life-threatening spike in blood pressure with evidence of acute organ damage, such as stroke, heart attack, or kidney failure. I16.1 sits in the ICD-10-CM chapter for diseases of the circulatory system (i00-i99), within the section covering hypertensive diseases (i10-i1a).

I16.1 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.

Maps to RxHCC 187 (Hypertension) with a RAF weight of 0.000 in the prescription drug model. Does NOT map directly to CMS-HCC v28, v24, or ESRD models. However, the acute organ damage codes that accompany hypertensive emergency (acute heart failure, acute MI, acute renal failure) may carry significant HCC values. Always code the specific organ damage to capture the full risk adjustment impact.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for I16.1 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Always code the associated end-organ damage (e.g., acute coronary syndrome, acute kidney injury) as additional diagnoses
•This code indicates a true medical emergency requiring immediate intervention

Clinical Significance

Hypertensive emergency is a life-threatening condition with severely elevated blood pressure AND acute target organ damage, which may include hypertensive encephalopathy, acute heart failure, acute coronary syndrome, acute renal failure, or aortic dissection. This requires immediate parenteral antihypertensive therapy and intensive care management, reflecting extremely high clinical acuity.

Documentation Requirements

✓Severely elevated blood pressure reading documented
✓Provider diagnosis of hypertensive emergency
✓Documentation of acute target organ damage — specify which organ(s) are affected
✓Type of organ damage: encephalopathy, acute HF, acute MI, acute renal failure, retinopathy, aortic dissection, etc.
✓Treatment with intravenous antihypertensives documented
✓ICU or monitored bed admission documentation
✓Additional codes for the specific organ damage should be assigned
✓Underlying hypertension diagnosis should also be coded

Code Also

, if applicable, to identify specific organ dysfunction, such as:
acute kidney injury (N17.-)
acute myocardial infarction (I21.-)
acute pulmonary edema (left and/or right ventricular failure) (J81.0, I50.-)
aortic dissection (I71.0-)
cerebral hemorrhage (I60.-. I61.-, I62.-)
cerebral infarction (I63.-)
eclampsia (O15.-)
hypertensive encephalopathy (I67.4)
seizure (R56.9)

Commonly Confused Codes

•I16.0: Hypertensive urgency (use when severely elevated BP is present WITHOUT organ damage)
•I16.9: Hypertensive crisis, unspecified (use only when urgency vs. emergency cannot be distinguished)
•I67.4: Hypertensive encephalopathy (specific type of organ damage that should be coded in addition to I16.1)
•I10: Essential hypertension (underlying condition; I16.1 is the acute event)

Child Codes

I16.0Hypertensive urgency

I16.1Hypertensive emergency

I16.9Hypertensive crisis, unspecified

Code Hierarchy

└I16Hypertensive crisis └I16.1Hypertensive emergency

└I16.1Hypertensive emergency

HCC Buddy Code Card

I16.1

Is I16.1 an HCC code?

HCC Category Mapping

MEAT Criteria for I16.1

What This Code Means

Coding Tips

Clinical Significance

Documentation Requirements

Code Also

Commonly Confused Codes

Child Codes

Code Hierarchy

More on I16.1

Referenced in blog posts

Open I16.1 in the Interactive Encoder

I16.1 ICD-10-CM Code: Hypertensive emergency

HCC Buddy Code Card

I16.1

Is I16.1 an HCC code?

HCC Category Mapping

MEAT Criteria for I16.1

What This Code Means

Coding Tips

Clinical Significance

Documentation Requirements

Code Also

Commonly Confused Codes

Child Codes

Code Hierarchy

More on I16.1

Referenced in blog posts

Open I16.1 in the Interactive Encoder