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I78.9 ICD-10-CM Code: Disease of capillaries, unspecified

I78.9 is not a CMS-HCC payment code. MEAT criteria · RAF Calculator · free HCC coding tools

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FY 2026 Apr update / Diseases of the circulatory system (I00-I99) / Diseases of arteries, arterioles and capillaries (I70-I79)

I78.9

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

Disease of capillaries, unspecified

This code describes a disease or disorder affecting the tiny blood vessels called capillaries, but the specific type of capillary disease has not been identified or documented. Capillaries are the smallest blood vessels in the body that connect arteries to veins.

CMS-HCC V28

N/A

—

Not mapped

CMS-HCC V24

N/A

—

Not mapped

ACA/HHS

N/A

—

Not mapped

ESRD/PACE

N/A

—

Not mapped

RXHCC

N/A

—

Not mapped

Code Book Path

Official
I78Diseases of capillaries
I78.9Disease of capillaries, unspecified

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for I78.9 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for I78.9 in this effective period.

Related Child Codes

Official
I78.0Hereditary hemorrhagic telangiectasia
I78.1Nevus, non-neoplastic
I78.8Other diseases of capillaries

Includes

Official

ICD-10-CM does not list Includes notes for I78.9 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for I78.9 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for I78.9 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for I78.9 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for I78.9 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance
Use this code only when the capillary disease is unspecified or when more specific information is not available in the medical record; always attempt to obtain clarification from the provider about the specific type of capillary disease
Review the clinical documentation for any symptoms or findings that might indicate a more specific capillary disorder (such as hereditary hemorrhagic telangiectasia, capillary malformation, or other specified capillary diseases) that would allow for a more precise code selection

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 I78.9 an HCC code?

No. I78.9 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.

Code
I78.9
Description
Disease of capillaries, unspecified
HCC (V28)
No CMS-HCC V28 mapping
RAF reference coefficient
—
Billable
Yes
Payment year
2026

Coder workflow notes

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This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).

What This Code Means

I78.9 is the ICD-10-CM diagnosis code for disease of capillaries, unspecified. This code describes a disease or disorder affecting the tiny blood vessels called capillaries, but the specific type of capillary disease has not been identified or documented. Capillaries are the smallest blood vessels in the body that connect arteries to veins. I78.9 sits in the ICD-10-CM chapter for diseases of the circulatory system (i00-i99), within the section covering diseases of arteries, arterioles and capillaries (i70-i79).

I78.9 is a billable ICD-10-CM code, but the current payload does not show a mapping under the CMS-HCC V28, V24, ESRD, or RxHCC models. Do not assign risk adjustment value from this page when no source-backed mapping is shown; verify the applicable model and payment year.

Use this code only when the capillary disease is unspecified or when more specific information is not available in the medical record; always attempt to obtain clarification from the provider about the specific type of capillary disease.

HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for I78.9 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

  • •Use this code only when the capillary disease is unspecified or when more specific information is not available in the medical record; always attempt to obtain clarification from the provider about the specific type of capillary disease
  • •Review the clinical documentation for any symptoms or findings that might indicate a more specific capillary disorder (such as hereditary hemorrhagic telangiectasia, capillary malformation, or other specified capillary diseases) that would allow for a more precise code selection

Child Codes

I78.0Hereditary hemorrhagic telangiectasia
I78.1Nevus, non-neoplastic
I78.8Other diseases of capillaries
I78.9Disease of capillaries, unspecified

Code Hierarchy

└I78Diseases of capillaries└I78.9Disease of capillaries, unspecified
└I78.9Disease of capillaries, unspecified

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