2027 ICD-10-CM Diagnosis Code G99.2Myelopathy in diseases classified elsewhere
ICD-10-CM Codes›G00–G99›G89-G99›G99
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Risk Adjusts — HCC 182
- Chronic Condition
G99.2 is a billable ICD-10-CM diagnosis code for myelopathy in diseases classified elsewhere. 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. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 156 closely related codes. The code is a manifestation code that cannot be reported as the principal diagnosis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other nervous system disorders (often hereditary or degenerative).
For Medicare Advantage risk adjustment, G99.2 maps to CMS-HCC Category 182 (Spinal Cord Disorders/Injuries) under the V28 model, adding a risk factor of about 0.478 for a community, non-dual, aged beneficiary in payment year 2027.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for G99.2.
Medicare Risk Adjustment (HCC)Billing
G99.2 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.
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.
- Central cord syndrome due to neoplasm
- Central cord syndrome due to syringomyelia
- Cervical myelopathy
- Disorder of spinal cord co-occurrent with human immunodeficiency virus infection
- Myelopathy due to another disorder
- Myelopathy due to benign neoplastic disease
- Myelopathy due to copper deficiency
- Myelopathy due to fluorosis
- Myelopathy due to folate deficiency
- Myelopathy due to liver disease
- Myelopathy due to malignant neoplastic disease
- Myelopathy due to metabolic disorder
- Myelopathy due to neoplastic disease
- Myelopathy due to nutritional deficiency
- Myelopathy due to obesity
- Myelopathy due to vitamin B12 deficiency
- Myelopathy with AIDS
- Neurological disorder due to obesity
- Spinal stenosis in cervical region
- Spinal stenosis in cervical region with myelopathy
- Syringomyelia
- Vacuolar myelopathy
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to G99.2: its own notes plus those printed at Chapter 6. A note printed at a category, block or chapter applies to every code under it.
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
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.
- 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)
Code First
The underlying condition named in the note is sequenced before this code.
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.
Patient EducationClinical
Spinal Cord Diseases
Your spinal cord is a bundle of nerves that runs down the middle of your back. It carries signals back and forth between your body and your brain. It is protected by your vertebrae, which are the bone disks that make up your spine.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert G99.2 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About G99.2Overview
What is the ICD-10 code for myelopathy in diseases classified elsewhere?
The ICD-10-CM code for myelopathy in diseases classified elsewhere is G99.2 (sometimes written as G992). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is G99.2 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report myelopathy in diseases classified elsewhere on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does G99.2 group to?
On inpatient claims, myelopathy in diseases classified elsewhere maps to MS-DRG 91, 92, 93, with relative weights from 0.7783 to 1.7050 depending on complications. Higher weights mean higher Medicare reimbursement.
Is G99.2 a CC or MCC?
CMS lists G99.2 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 156 closely related codes in its exclusion list.
Can G99.2 be a principal diagnosis?
No. This is a manifestation code: myelopathy in diseases classified elsewhere describes the manifestation of an underlying disease rather than the disease itself, so the underlying condition is sequenced first.
What HCC is G99.2?
G99.2 (myelopathy in diseases classified elsewhere) maps to CMS-HCC Category 182 (Spinal Cord Disorders/Injuries), commonly written as HCC 182, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 72 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 155.
Does G99.2 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, G99.2 adds a risk adjustment factor of about 0.478 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.270 to 0.478 depending on the payment segment). A more severe related category (HCC 180, HCC 181, HCC 191, and HCC 192) supersedes it when both are reported. See the full factor table on the HCC 182 category page.
