2026 ICD-10-CM Diagnosis Code S13.110DSubluxation of C0/C1 cervical vertebrae, subsequent encounter
S13.110D is a billable ICD-10-CM diagnosis code for subluxation of C0/C1 cervical vertebrae, 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 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 949 through 950. The code is exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Dislocations, subsequent encounter.
Code Identity
Code Classification
Present on Admission (POA)Billing
S13.110D is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Closed dislocation atlanto-occipital joint
- Closed subluxation atlanto-occipital joint
- Dislocation of atlanto-occipital joint
- Open dislocation atlanto-occipital joint
- Open dislocation of first cervical vertebra
- Open subluxation atlanto-occipital joint
- Subluxation of atlanto-occipital joint
- Traumatic dislocation of atlanto-occipital joint
- Traumatic subluxation of atlanto-occipital joint
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Dislocation and sprain of joints and ligaments at neck level (S13). 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 2026, published by CMS and the National Center for Health Statistics.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Dislocations
Dislocations are joint injuries that force the ends of your bones out of position. The cause is often a fall or a blow, sometimes from playing a contact sport. You can dislocate your ankles, knees, shoulders, hips, elbows and jaw. You can also dislocate your finger and toe joints.
Read the full article at MedlinePlus
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Convert S13.110D to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S13.110DOverview
Is S13.110D (Subluxation of C0/C1 cervical vertebrae) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report subluxation of C0/C1 cervical vertebrae, subsequent encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character D in S13.110D mean?
The final character D marks a subsequent encounter: use it for routine care while the subluxation of C0/C1 cervical vertebrae is healing, after active treatment has ended.
What MS-DRG does S13.110D group to?
When subluxation of C0/C1 cervical vertebrae, subsequent encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 949, 950, with relative weights from 0.6277 to 1.1897 depending on complications. Higher weights mean higher Medicare reimbursement.
Is S13.110D 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 subluxation of C0/C1 cervical vertebrae, subsequent encounter on inpatient claims.
What is the ICD-9 equivalent of S13.110D?
Under the General Equivalence Mappings, subluxation of C0/C1 cervical vertebrae, subsequent encounter converts to ICD-9-CM V58.89 (other specfied aftercare). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
