S12.000K Unspecified displaced fracture of first cervical vertebra, subsequent encounter for fracture with nonunion

ICD-10-CM S12.000K: Unspecified displaced fracture of first cervical vertebra, subsequent encounter for fracture with nonunion

ICD-10-CM code S12.000K designates an unspecified displaced fracture of the first cervical vertebra during a subsequent encounter for fracture with nonunion. The concept is an active injury or poisoning terminology record with a parent code of S12.000. This code also appears in a Medicare cervical fusion billing article. 1 3

Plain-language overview

Code S12.000K identifies a subsequent clinical encounter for an unspecified displaced fracture of the first cervical vertebra where the fracture has resulted in nonunion. 1

What this code represents

The terminology record classifies S12.000K with the semantic type of Injury or Poisoning and establishes its parent concept as S12.000, the unspecified displaced fracture of the first cervical vertebra. 1

The official published abbreviation for S12.000K is unsp disp fx of first cervcal vert, subs for fx w nonunion, and the terminology record indicates the concept currently holds an active status. 1

Coding details

Code S12.000K belongs to chapter nineteen of the ICD-10-CM coding system, which encompasses the S10-S19 block for injuries to the neck region, and is listed alongside related codes like S12.091K. 5

Documentation considerations

For related code S12.000B to count as a valid HCC diagnosis, provider documentation must satisfy MEAT criteria by showing the provider monitored, evaluated, assessed, or treated the condition during that specific encounter. 4

Coverage and utilization context

Code S12.000K appears in a Medicare billing and coding article for cervical fusion, which lists the diagnosis code alongside S12.000S within the same document. 3

What the sources add

The official terminology record establishes S12.000K as an active injury concept, while a separate clinical reference describes the first cervical vertebra, or atlas, as part of the C1 to C2 complex that lacks an intervertebral disc. 1 2

While the official terminology record defines S12.000K as an active injury concept with narrower concepts, a third-party billing site lists the code within the S10-S19 neck injury block alongside S12.091K. 1 5

Questions to verify

The supplied excerpts do not establish whether S12.000K is a billable code, nor do they define the specific clinical documentation elements required to support the subsequent encounter or nonunion designation for this exact code. 1 4

Sources

1. ICD-10-CM S12.000K terminology record — National Cancer Institute Enterprise Vocabulary Services; accessed 2026-07-27.
2. Bookshelf — ncbi.nlm.nih.gov; accessed 2026-07-27.
3. Article - Billing and Coding: Cervical Fusion (A59645) — cms.gov; accessed 2026-07-27.
4. 2026 ICD-10-CM S12.000B: Unspecified displaced | HCC 401 — hccbuddy.com; accessed 2026-07-27.
5. Codigo. The #1 Billing Agency for Medical Practices — codigo.care; accessed 2026-07-27.