2027 ICD-10-CM Diagnosis Code G83.83Posterior cord syndrome

ICD-10-CM Codes›G00–G99›G80-G83›G83

ICD-10-CM G83.83
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

G83.83 is a billable ICD-10-CM diagnosis code for posterior cord syndrome. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 91 through 93. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Paralysis (other than cerebral palsy).

For Medicare Advantage risk adjustment, G83.83 maps to CMS-HCC Category 254 (Monoplegia, Other Paralytic Syndromes) under the V28 model, adding a risk factor of about 0.321 for a community, non-dual, aged beneficiary in payment year 2027.

Code Identity

ICD-10-CM Code
G83.83
Billable Status
Yes — Valid for Submission
Code Describes
Posterior cord syndrome
Short Description
Posterior cord syndrome
Same as the full description in the CMS dataset.
Parent Code
Other specified paralytic syndromes

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG80-G83Cerebral palsy and other paralytic syndromes
CategoryG83Other paralytic syndromes
This CodeG83.83Posterior cord syndrome

Medicare Risk Adjustment (HCC)Billing

G83.83 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.

CMS-HCC V28 Category (Payment Model)
HCC 254— Monoplegia, Other Paralytic Syndromes
Payment HCC · PY 2027 one of 119 ICD-10-CM codes in this category
Risk Adjustment Factor (RAF) Weight
+0.321
community, non-dual, aged · ranges 0.000–0.365 across segments
Hierarchy
Superseded by HCC 180, HCC 181, HCC 191, HCC 192, and HCC 253
a more severe related category takes the payment when both are reported
Prior Model (CMS-HCC V24)
HCC 104
V24 retired V28 pays 100% of MA risk scores since PY 2026
Other CMS Models
PACE (CMS-HCC V22): HCC 104 · ESRD (V21): HCC 104 · ESRD (V24): HCC 104
ESRD V21 weights: 0.077 dialysis, 0.000–0.307 functioning graft · ESRD V24 weights: 0.047 dialysis, 0.013–0.353 functioning graft
Part D (RxHCC)
Not mapped
G83.83 does not risk-adjust in the RxHCC prescription drug model

Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Cerebellar ataxia associated with another disorder
  • Demyelination of spinal cord
  • Friedreich ataxia
  • Multiple sclerosis of the spinal cord
  • Posterior cord syndrome
  • Posterior cord syndrome due to cervical spondylosis
  • Posterior cord syndrome due to Friedreich ataxia
  • Posterior cord syndrome due to multiple sclerosis
  • Posterior cord syndrome due to neoplasm
  • Posterior cord syndrome due to tabetic neurosyphilis
  • Posterior cord syndrome due to vascular malformation
  • Tabetic neurosyphilis
  • Traumatic posterior cord syndrome

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to G83.83: its own notes plus those printed at G83.8, G83, and Chapter 6. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From G83 Other paralytic syndromes applies to 24 codes
  • paralysis (complete) (incomplete), except as in G80-G82

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From G83.8 Other specified paralytic syndromes applies to 5 codes
  • paralytic syndromes due to current spinal cord injury-code to spinal cord injury (S14, S24, S34)

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.

From Chapter 6 (G00-G99) Diseases of the nervous system applies to 700 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Notes

General instructions on how these codes are used.

From G83 Other paralytic syndromes applies to 24 codes
  • This category is to be used only when the listed conditions are reported without further specification, or are stated to be old or longstanding but of unspecified cause. The category is also for use in multiple coding to identify these conditions resulting from any cause.

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NVS008
Paralysis (other than cerebral palsy)
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Posterior Cord Syndrome

    a syndrome caused by insult to the posterior columns of the spinal cord and resulting in impairments of proprioception, vibration, and fine touch. typical presenting signs and symptoms may include sensory ataxia, dizziness, unsteady gait, and frequent falls.

Patient EducationClinical

Paralysis

Paralysis is the loss of muscle function in part of your body. It happens when something goes wrong with the way messages pass between your brain and muscles. Paralysis can be complete or partial. It can occur on one or both sides of your body. It can also occur in just one area, or it can be widespread.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert G83.83 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
344.89 Oth spcf paralytic synd
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About G83.83Overview

What is the ICD-10 code for posterior cord syndrome?

The ICD-10-CM code for posterior cord syndrome is G83.83 (sometimes written as G8383). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is G83.83 (Other specified paralytic syndromes) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report posterior cord syndrome on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does G83.83 group to?

When posterior cord syndrome is the principal diagnosis on an inpatient stay, it groups to MS-DRG 91, 92, 93, with relative weights from 0.7783 to 1.7050 depending on complications. Higher weights mean higher Medicare reimbursement.

Can G83.83 be reported with S14?

Not as a rule. The Excludes1 note at G83.8, which applies to G83.83, lists "paralytic syndromes due to current spinal cord injury-code to spinal cord injury (S14, S24, S34)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

What is the ICD-9 equivalent of G83.83?

Under the General Equivalence Mappings, posterior cord syndrome converts to ICD-9-CM 344.89 (oth spcf paralytic synd). The mapping is approximate, so confirm the match fits the documentation.

What HCC is G83.83?

G83.83 (posterior cord syndrome) maps to CMS-HCC Category 254 (Monoplegia, Other Paralytic Syndromes), commonly written as HCC 254, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 104 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. It does not map to any RxHCC in the Part D prescription drug model.

Does G83.83 risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, G83.83 adds a risk adjustment factor of about 0.321 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.000 to 0.365 depending on the payment segment). A more severe related category (HCC 180, HCC 181, HCC 191, HCC 192, and HCC 253) supersedes it when both are reported. See the full factor table on the HCC 254 category page.