What is ICD-10 code G99.2?

G99.2 is the ICD-10-CM diagnosis code for Myelopathy in diseases classified elsewhere. It belongs to the ICD-10-CM chapter for diseases of the nervous system (g00-g99). G99.2 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. G99.2 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. G99.2 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. G99.2 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Which HCC does G99.2 map to under V28?

G99.2 maps to CMS-HCC V28 HCC 182 (Spinal Cord Disorders/Injuries). The category numbers, labels, and conditions come from the CMS-HCC V28 model file for payment year 2026.

2026 ICD-10-CM G99.2: Myelopathy in diseases

G99.2 maps to CMS-HCC V28 182. A source-labeled RAF reference is available. Confirm the documented diagnosis and applicable coding requirements. MEAT criteria · RAF Calculator · free HCC coding tools

ICD-10-CM Code View

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Code lookupG99.2

Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Diseases of the nervous system (G00-G99) / Other disorders of the nervous system (G89-G99)

G99.2

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Myelopathy in diseases classified elsewhere

This code describes damage or disease of the spinal cord that is caused by another medical condition listed elsewhere in the medical record. The spinal cord damage results from an underlying disease rather than being a primary spinal cord disorder.

Buddy Insight

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

CMS-HCC V28

Mapped

HCC 182

Spinal Cord Disorders/Injuries

Code-level coefficient reference

CMS-HCC V24

Historical

Not used for standard CY2026 Medicare Advantage payment. Select a historical period to review V24.

Not used for CY2026 payment

ACA/HHS

Mapped

HCC 110

HHS-HCC 110 adult, RAF varies...

Code-level coefficient reference

ESRD/PACE

Mapped

HCC 72

Spinal Cord Disorders/Injuries

Code-level coefficient reference

RXHCC

Mapped

HCC 155

Spinal Cord Disorders

Code-level coefficient reference

Code Book Path

Official

G99Other disorders of nervous system in diseases classified elsewhere G99.2Myelopathy in diseases classified elsewhere

Inclusion Terms

Official

No inclusion terms are included in this display for G99.2. Check the code and parent instructions in the Code Book.

Excludes 2

Official

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

Related Codes

Official

G99.0Autonomic neuropathy in diseases classified elsewhere G99.8Other specified disorders of nervous system in diseases classified elsewhere

Includes

Official

No Includes notes are included in this display for G99.2. Check the code and parent instructions in the Code Book.

Excludes 1

Official

myelopathy in:
intervertebral disease (M50.0-, M51.0-)
spondylosis (M47.0-, M47.1-)

Code First

Official

underlying disease, such as:
neoplasm (C00-D49)

Use Additional

Official

No Use Additional Code instructions are included in this display for G99.2. Check the code and parent instructions in the Code Book.

Code Also

Official

No Code Also instructions are included in this display for G99.2. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

Documentation of the underlying disease causing the myelopathy

Clinical evidence of spinal cord dysfunction (myelopathic signs on examination)

Causal relationship between the underlying disease and the myelopathy documented by the provider

Imaging or other diagnostic evidence supporting spinal cord involvement

MEAT Support

HCC Buddy guidance

Documentation of the underlying disease causing the myelopathy

Clinical evidence of spinal cord dysfunction (myelopathic signs on examination)

Causal relationship between the underlying disease and the myelopathy documented by the provider

Imaging or other diagnostic evidence supporting spinal cord involvement

Audit Caution

HCC Buddy guidance

Coding G99.2 without first coding the underlying disease — this is a manifestation code that requires sequencing

Using this code when the underlying condition already has a combination code that includes myelopathy (e.g., spondylotic myelopathy)

Not documenting the causal link between the underlying disease and the spinal cord dysfunction

Confusing myelopathy (spinal cord) with neuropathy (peripheral nerves) or encephalopathy (brain)

Common Mistakes

HCC Buddy guidance

G95.89 — Other specified diseases of spinal cord: use when the myelopathy is not secondary to a separately classified disease

G95.9 — Disease of spinal cord, unspecified: less specific, does not capture the manifestation relationship

M47.10 — Other spondylosis with myelopathy: spondylotic myelopathy has its own specific code and does not need G99.2

G95.11 — Acute infarction of spinal cord: specific vascular cause, not a manifestation of another disease

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is G99.2 an HCC code?

Yes. G99.2 (Myelopathy in diseases classified elsewhere) maps to HCC 182, Spinal Cord Disorders/Injuries under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 0.478. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes. It is billable for payment year 2026.

Coder answer: G99.2 is billable and maps to V28 HCC 182, Spinal Cord Disorders/Injuries. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: G99.2
Description: Myelopathy in diseases classified elsewhere
HCC (V28): HCC 182 — Spinal Cord Disorders/Injuries
RAF reference coefficient: 0.478
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 182, Spinal Cord Disorders/Injuries

0.478

ESRDHCC 72, Spinal Cord Disorders/Injuries

Not separately weighted

RxHCCHCC 155, Spinal Cord Disorders

Not separately weighted

These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. Weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.

Work G99.2 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for G99.2

For G99.2, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.

MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
EEvaluate: test results, medication response, or physical findings reviewed by the provider
AAssess: explicit mention in the assessment or plan with acknowledgment of status
TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Coder workflow notes

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What This Code Means

G99.2 is the ICD-10-CM diagnosis code for myelopathy in diseases classified elsewhere. This code describes damage or disease of the spinal cord that is caused by another medical condition listed elsewhere in the medical record. The spinal cord damage results from an underlying disease rather than being a primary spinal cord disorder. G99.2 sits in the ICD-10-CM chapter for diseases of the nervous system (g00-g99), within the section covering other disorders of the nervous system (g89-g99).

Under the CMS-HCC V28 risk adjustment model, G99.2 maps to Spinal Cord Disorders/Injuries (HCC 182) with a source-labeled community, non-dual, aged reference coefficient of 0.478. No V24 mapping is shown for G99.2; use the applicable model and payment year when reviewing the V28 mapping. For CY2026 non-PACE Medicare Advantage, CMS uses 100% of the 2024 CMS-HCC model (V28). PACE uses a separate model blend. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes.

This is a secondary diagnosis code that requires an underlying condition code to be reported first; always identify and code the primary disease causing the myelopathy. For G99.2, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.

HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for G99.2 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•This is a secondary diagnosis code that requires an underlying condition code to be reported first; always identify and code the primary disease causing the myelopathy
•Common underlying conditions include syphilis (A52.14), HIV (B20), vitamin B12 deficiency (E53.8), and other systemic diseases; ensure the causal relationship is documented in the medical record

Clinical Significance

Myelopathy in diseases classified elsewhere is a manifestation code used when spinal cord dysfunction occurs as a result of an underlying classified condition, such as cervical spondylosis, systemic lupus erythematosus, or vitamin B12 deficiency. Proper use requires coding the underlying condition first, followed by G99.2. This dual-coding approach accurately represents the complexity of the patient's condition and its impact on the spinal cord.

Documentation Requirements

✓Documentation of the underlying disease causing the myelopathy
✓Clinical evidence of spinal cord dysfunction (myelopathic signs on examination)
✓Causal relationship between the underlying disease and the myelopathy documented by the provider
✓Imaging or other diagnostic evidence supporting spinal cord involvement
✓Current functional status and treatment plan for both the underlying disease and the myelopathy

Excludes 1, Do NOT code together

myelopathy in:
intervertebral disease (M50.0-, M51.0-)
spondylosis (M47.0-, M47.1-)

Code First

underlying disease, such as:
neoplasm (C00-D49)

Commonly Confused Codes

•G95.89: Other specified diseases of spinal cord: use when the myelopathy is not secondary to a separately classified disease
•G95.9: Disease of spinal cord, unspecified: less specific, does not capture the manifestation relationship
•M47.10: Other spondylosis with myelopathy: spondylotic myelopathy has its own specific code and does not need G99.2
•G95.11: Acute infarction of spinal cord: specific vascular cause, not a manifestation of another disease