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S21.159S ICD-10-CM Code: Open bite of unspecified front wall of thorax without penetration into thoracic cavity, sequela

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FY 2026 Apr update / Injury, poisoning and certain other consequences of external causes (S00-T88) / Injuries to the thorax (S20-S29)

S21.159S

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

Open bite of unspecified front wall of thorax without penetration into thoracic cavity, sequela

Open bite of unspecified front wall of thorax without penetration into thoracic cavity, sequela

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
S21.15Open bite of front wall of thorax without penetration into thoracic cavity
S21.159Open bite of unspecified front wall of thorax without penetration into thoracic cavity
S21.159SOpen bite of unspecified front wall of thorax without penetration into thoracic cavity, sequela

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for S21.159S in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for S21.159S in this effective period.

Related Child Codes

Official
S21.159AOpen bite of unspecified front wall of thorax without penetration into thoracic cavity, initial encounter
S21.159DOpen bite of unspecified front wall of thorax without penetration into thoracic cavity, subsequent encounter

Includes

Official

ICD-10-CM does not list Includes notes for S21.159S in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for S21.159S in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for S21.159S in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for S21.159S in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for S21.159S 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 S21.159S an HCC code?

No. S21.159S 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

S21.159S is the ICD-10-CM diagnosis code for open bite of unspecified front wall of thorax without penetration into thoracic cavity, sequela. S21.159S 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 thorax (s20-s29).

S21.159S 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.

S21.159S 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 S21.159S 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 S21.159S 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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