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S55.999D ICD-10-CM Code: Other specified injury of unspecified blood vessel at forearm level, unspecified arm, subsequent encounter

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FY 2026 Apr update / Injury, poisoning and certain other consequences of external causes (S00-T88) / Injuries to the elbow and forearm (S50-S59)

S55.999D

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

Other specified injury of unspecified blood vessel at forearm level, unspecified arm, subsequent encounter

Other specified injury of unspecified blood vessel at forearm level, unspecified arm, subsequent encounter

CMS-HCC V28

0

0

RAF 0

CMS-HCC V24

0

0

RAF 0

ACA/HHS

0

0

RAF 0

ESRD/PACE

0

0

RAF 0

RXHCC

0

0

RAF 0

Code Trumping

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Code Book Path

Official
S55.99Other specified injury of unspecified blood vessel at forearm level
S55.999Other specified injury of unspecified blood vessel at forearm level, unspecified arm
S55.999DOther specified injury of unspecified blood vessel at forearm level, unspecified arm, subsequent encounter

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for S55.999D in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for S55.999D in this effective period.

Related Child Codes

Official
S55.999AOther specified injury of unspecified blood vessel at forearm level, unspecified arm, initial encounter
S55.999SOther specified injury of unspecified blood vessel at forearm level, unspecified arm, sequela

Includes

Official

ICD-10-CM does not list Includes notes for S55.999D in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for S55.999D in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for S55.999D in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for S55.999D in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for S55.999D in this effective period.

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 S55.999D an HCC code?

No. S55.999D is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.

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

What This Code Means

S55.999D is the ICD-10-CM diagnosis code for other specified injury of unspecified blood vessel at forearm level, unspecified arm, subsequent encounter. S55.999D sits in the ICD-10-CM chapter for injury, poisoning and certain other consequences of external causes (s00-t88), within the section covering injuries to the elbow and forearm (s50-s59).

S55.999D 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.

S55.999D is a billable ICD-10-CM code that can be reported on claims but does not currently contribute to a Medicare Advantage member's RAF score under any CMS risk adjustment model (V28, V24, ESRD, or RxHCC). Coders reviewing S55.999D 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 S55.999D sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Child Codes

Code Hierarchy

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