2027 ICD-10-CM Diagnosis Code S55.909DUnspecified injury of unspecified blood vessel at forearm level, unspecified arm, subsequent encounter
S55.909D is a billable ICD-10-CM diagnosis code for unspecified injury of unspecified blood vessel at forearm level, unspecified arm, subsequent encounter. The 7th character D marks it as a subsequent encounter code, used during routine care in the healing or recovery phase. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 949 through 950. The code is exempt from POA reporting. Coders also document this condition as injury of blood vessels at forearm level. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Injury to blood vessels, subsequent encounter.
Code Identity
Code Classification
Present on Admission (POA)Billing
S55.909D is exempt from POA reporting on inpatient claims to general acute care hospitals. Review the other POA exempt codes in Injuries to the elbow and forearm (S50-S59).
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Injury of blood vessels at forearm level
- Injury of multiple blood vessels at forearm level
- Injury of multiple blood vessels of upper extremity
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Injury of blood vessels at forearm level (S55). 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 S55.909D: its own notes plus those printed at S55, block S50-S59, and Chapter 19. A note printed at a category, block or chapter applies to every code under it.
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.
Use Additional Code
Add a second code, after this one, to fully describe the condition.
- 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.
Notes
General instructions on how these codes are used.
- 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.
- The appropriate 7th character is to be added to each code from category S55
- Ainitial encounter
- Dsubsequent encounter this code
- 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.
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 S55.909D to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S55.909DOverview
Is S55.909D a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report unspecified injury of unspecified blood vessel at forearm level, unspecified arm, subsequent encounter on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What does the 7th character D in S55.909D mean?
The final character D marks a subsequent encounter: use it for routine care while the unspecified injury of unspecified blood vessel at forearm level, unspecified arm is healing, after active treatment has ended.
What MS-DRG does S55.909D group to?
When unspecified injury of unspecified blood vessel at forearm level, unspecified arm, subsequent encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 950, 949, with relative weights from 0.7661 to 1.1231 depending on complications. Higher weights mean higher Medicare reimbursement.
Is S55.909D exempt from POA reporting?
Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for unspecified injury of unspecified blood vessel at forearm level, unspecified arm, subsequent encounter on inpatient claims. The code appears in the Injuries to the elbow and forearm (S50-S59) range of the CMS exempt list.
What is the ICD-9 equivalent of S55.909D?
Under the General Equivalence Mappings, unspecified injury of unspecified blood vessel at forearm level, unspecified arm, subsequent encounter converts to ICD-9-CM V58.89 (other specfied aftercare). The mapping is approximate, so confirm the match fits the documentation.
