S23.121A – Dislocation of T2/T3 thoracic vertebra, initial encounter

ICD-10-CM 2027 diagnosis code · Injuries to the thorax

Billable code

ICD-10-CM code S23.121A

Code: S23.121A (claims format: S23121A)
Description: Dislocation of T2/T3 thoracic vertebra, initial encounter
Billable: Yes – valid for HIPAA-covered transactions
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 19. Injury, poisoning and certain other consequences of external causes (S00-T88)
Block: S20-S29 Injuries to the thorax
Parent codes: S23 › S23.1 › S23.12 › S23.121

7th character values

Codes in this category need a 7th character to describe the encounter or episode of care.

Character	Meaning
`A`	initial encounter
`D`	subsequent encounter
`S`	sequela

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

S23 – Dislocation and sprain of joints and ligaments of thorax

Includes:

avulsion of joint or ligament of thorax
laceration of cartilage, joint or ligament of thorax
sprain of cartilage, joint or ligament of thorax
traumatic hemarthrosis of joint or ligament of thorax
traumatic rupture of joint or ligament of thorax
traumatic subluxation of joint or ligament of thorax
traumatic tear of joint or ligament of thorax

Excludes2 (not included here):

dislocation, sprain of sternoclavicular joint (S43.2, S43.6)
strain of muscle or tendon of thorax (S29.01-)

Code also:

any associated open wound

7th character note:

The appropriate 7th character is to be added to each code from category S23

S23.1 – Subluxation and dislocation of thoracic vertebra

Excludes2 (not included here):

fracture of thoracic vertebrae (S22.0-)

Code also:

any associated:
open wound of thorax (S21.-)
spinal cord injury (S24.0-, S24.1-)

Block S20-S29

Includes:

injuries of breast
injuries of chest (wall)
injuries of interscapular area

Excludes2 (not included here):

burns and corrosions (T20-T32)
effects of foreign body in bronchus (T17.5)
effects of foreign body in esophagus (T18.1)
effects of foreign body in lung (T17.8)
effects of foreign body in trachea (T17.4)
frostbite (T33-T34)
injuries of axilla
injuries of clavicle
injuries of scapular region
injuries of shoulder
insect bite or sting, venomous (T63.4)

Related codes in S23.121

Frequently asked questions

What is ICD-10 code S23.121A?

S23.121A is the ICD-10-CM code for dislocation of T2/T3 thoracic vertebra, initial encounter, in the block S20-S29 (Injuries to the thorax).

Is S23.121A a billable code?

Yes. S23.121A is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.

What category does S23.121A belong to?

It belongs to category S23 – Dislocation and sprain of joints and ligaments of thorax.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.