2027 ICD-10-CM Diagnosis Code S45.902AUnspecified injury of unspecified blood vessel at shoulder and upper arm level, left arm, initial encounter

ICD-10-CM Codes›S00–T88›S40-S49›S45

ICD-10-CM S45.902A
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

S45.902A is a billable ICD-10-CM diagnosis code for unspecified injury of unspecified blood vessel at shoulder and upper arm level, left arm, initial encounter. The 7th character A marks it as an initial encounter code, used while the patient is receiving active treatment. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 913 through 914, 963 through 965. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 96 closely related codes. Coders also document this condition as injury of blood vessel of left upper arm. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Injury to blood vessels, initial encounter.

Code Identity

ICD-10-CM Code
S45.902A
Billable Status
Yes — Valid for Submission
Code Describes
Unspecified injury of unspecified blood vessel at shoulder and upper arm level, left arm, initial encounter
Short Description
Unsp inj unsp blood vess at shldr/up arm, left arm, init
Parent Code
S45.902
Unspecified injury of unspecified blood vessel at shoulder and upper arm level, left arm

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS40-S49Injuries to the shoulder and upper arm
CategoryS45Injury of blood vessels at shoulder and upper arm level
This CodeS45.902AUnspecified injury of unspecified blood vessel at shoulder and upper arm level, left arm, initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Injury of blood vessel of left upper arm
  • Injury of blood vessel of upper arm

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Injury of blood vessels at shoulder and upper arm level (S45). Use the following options for the applicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027, published by CMS and the National Center for Health Statistics.

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to S45.902A: its own notes plus those printed at S45, block S40-S49, and Chapter 19. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From Block S40-S49 Injuries to the shoulder and upper arm applies to 2,730 codes
  • injuries of axilla
  • injuries of scapular region

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From S45 Injury of blood vessels at shoulder and upper arm level applies to 162 codes
  • injury of subclavian artery (S25.1)
  • injury of subclavian vein (S25.3)
From Block S40-S49 Injuries to the shoulder and upper arm applies to 2,730 codes
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • code to identify any retained foreign body, if applicable (Z18.-)

Code Also

A second code may be needed to fully describe the condition; the note gives no sequencing direction.

From S45 Injury of blood vessels at shoulder and upper arm level applies to 162 codes
  • any associated open wound (S41.-)

Notes

General instructions on how these codes are used.

From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
  • The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.

7th Character

Every code in the category takes a 7th character from the listed values, with the placeholder X filling any empty positions before it.

From S45 Injury of blood vessels at shoulder and upper arm level applies to 162 codes
  • The appropriate 7th character is to be added to each code from category S45
Values for category S45 Encounter: Initial, Subsequent, Sequela
  • Ainitial encounter this code
  • Dsubsequent encounter
  • Ssequela

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INJ016
Injury to blood vessels, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Arm Injuries and Disorders

Of the 206 bones in your body, three of them are in your arm: the humerus, radius, and ulna. Your arms are also made up of muscles, joints, tendons, and other connective tissue. Injuries to any of these parts of the arm can occur during sports, a fall, or an accident.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert S45.902A to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
903.9 Injury arm vessel NOS
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About S45.902AOverview

Is S45.902A a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report unspecified injury of unspecified blood vessel at shoulder and upper arm level, left arm, initial encounter on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What does the 7th character A in S45.902A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for unspecified injury of unspecified blood vessel at shoulder and upper arm level, left arm, such as an emergency visit or first evaluation.

What MS-DRG does S45.902A group to?

When unspecified injury of unspecified blood vessel at shoulder and upper arm level, left arm, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 964, 965, 914, 913, 963, with relative weights from 0.9281 to 2.6361 depending on complications. Higher weights mean higher Medicare reimbursement.

Is S45.902A a CC or MCC?

CMS lists S45.902A as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 96 closely related codes in its exclusion list.

What is the ICD-9 equivalent of S45.902A?

Under the General Equivalence Mappings, unspecified injury of unspecified blood vessel at shoulder and upper arm level, left arm, initial encounter converts to ICD-9-CM 903.9 (injury arm vessel NOS). The mapping is approximate, so confirm the match fits the documentation.