ICDcodes.org
FY2027

S23.100A — Subluxation of unspecified thoracic vertebra, initial encounter

BillableUnspecified

Is S23.100A billable?

Yes, but S23.100A is an unspecified code. S23.100A is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, S23.100A is an unspecified or catch-all code. Payers apply additional scrutiny to unspecified codes and many deny them when the medical record supports a more specific option, so check the documentation before selecting S23.100A — the more specific alternatives are listed below.

S23.100A at a glance

CodeS23.100A
DescriptionSubluxation of unspecified thoracic vertebra, initial encounter
BillableYes
Code setICD-10-CM FY2027
Valid for encountersOctober 1, 2026 – September 30, 2027
7th character "A"initial encounter

What does the 7th character "A" mean in S23.100A?

In S23.100A, the 7th character A means initial encounter. The 7th character is required for S23.100A to be a valid, complete code.

Same condition, different episode of care — switch the 7th character:

Which MS-DRGs does S23.100A group to?

S23.100A sits in MDC 08 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.

  • 551Medical Back Problems with MCCmedical
  • 552Medical Back Problems without MCCmedical

How is S23.100A listed in the Alphabetic Index?

The Alphabetic Index lists these routes under S23.100, the nearest indexed parent of S23.100A. Use them to find the family, then select the specific code.

  • Subluxation › vertebral › traumatic › thoracic

Use additional code — inherited from Chapter 19

Report an additional code alongside S23.100A to fully describe the condition. S23.100A is sequenced first.

  • code to identify any retained foreign body, if applicable (Z18.-)

Excludes2 — not included here — inherited from Chapter 19

The conditions below are not part of S23.100A, but a patient may have both at the same time. When documentation supports it, S23.100A and the excluded code may both be reported.

  • birth trauma (P10-P15)
  • obstetric trauma (O70-O71)

Excludes2 — not included here — inherited from S20-S29

The conditions below are not part of S23.100A, but a patient may have both at the same time. When documentation supports it, S23.100A and the excluded code may both be reported.

  • 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)

Excludes2 — not included here — inherited from S23

The conditions below are not part of S23.100A, but a patient may have both at the same time. When documentation supports it, S23.100A and the excluded code may both be reported.

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

Excludes2 — not included here — inherited from S23.1

The conditions below are not part of S23.100A, but a patient may have both at the same time. When documentation supports it, S23.100A and the excluded code may both be reported.

  • fracture of thoracic vertebrae (S22.0-)

Code also — inherited from S23

Two codes may be needed to describe the condition fully. Whether S23.100A is sequenced first depends on the reason for the encounter.

  • any associated open wound

Code also — inherited from S23.1

Two codes may be needed to describe the condition fully. Whether S23.100A is sequenced first depends on the reason for the encounter.

How long has S23.100A existed?

S23.100A has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.

Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.