2027 ICD-10-CM Diagnosis Code G12.25Progressive spinal muscle atrophy
ICD-10-CM Codes›G00–G99›G10-G14›G12
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Risk Adjusts — HCC 190
- Chronic Condition
G12.25 is a billable ICD-10-CM diagnosis code for progressive spinal muscle atrophy. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 56 through 57. 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 111 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other nervous system disorders (often hereditary or degenerative).
For Medicare Advantage risk adjustment, G12.25 maps to CMS-HCC Category 190 (Amyotrophic Lateral Sclerosis and Other Motor Neuron Disease, Spinal Muscular Atrophy) under the V28 model, adding a risk factor of about 1.175 for a community, non-dual, aged beneficiary in payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
G12.25 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.
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to G12.25: its own notes plus those printed at Chapter 6. A note printed at a category, block or chapter applies to every code under it.
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)
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.
Clinical InformationClinical
Motor Neuron Disease
diseases characterized by a selective degeneration of the motor neurons of the spinal cord, brainstem, or motor cortex. clinical subtypes are distinguished by the major site of degeneration. in amyotrophic lateral sclerosis there is involvement of upper, lower, and brainstem motor neurons. in progressive muscular atrophy and related syndromes (see muscular atrophy, spinal) the motor neurons in the spinal cord are primarily affected. with progressive bulbar palsy (bulbar palsy, progressive), the initial degeneration occurs in the brainstem. in primary lateral sclerosis, the cortical neurons are affected in isolation. (adams et al., principles of neurology, 6th ed, p1089)
Patient EducationClinical
Spinal Muscular Atrophy
Spinal muscular atrophy (SMA) is a group of genetic diseases that damages and kills motor neurons. Motor neurons are a type of nerve cell in the spinal cord and lower part of the brain. They control movement in your arms, legs, face, chest, throat, and tongue.
The full article covers:
- What is spinal muscular atrophy (SMA)?
- What are the types of spinal muscular atrophy (SMA) and what are their symptoms?
- What causes spinal muscular atrophy (SMA)?
- How is spinal muscular atrophy (SMA) diagnosed?
- What are the treatments for spinal muscular atrophy (SMA)?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert G12.25 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code History & ChangesHistory
Replacement G12.25 replaces the following previously assigned code(s):
- G12.21 - Amyotrophic lateral sclerosis
Questions About G12.25Overview
What is the ICD-10 code for progressive spinal muscle atrophy?
The ICD-10-CM code for progressive spinal muscle atrophy is G12.25 (sometimes written as G1225). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is G12.25 (Motor neuron disease) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report progressive spinal muscle atrophy on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does G12.25 group to?
When progressive spinal muscle atrophy is the principal diagnosis on an inpatient stay, it groups to MS-DRG 57, 56, with relative weights from 1.2835 to 2.2649 depending on complications. Higher weights mean higher Medicare reimbursement.
Is G12.25 a CC or MCC?
CMS lists G12.25 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 111 closely related codes in its exclusion list.
What is the ICD-9 equivalent of G12.25?
Under the General Equivalence Mappings, progressive spinal muscle atrophy converts to ICD-9-CM 335.10 (spinal muscl atrophy NOS). The mapping is approximate, so confirm the match fits the documentation.
What HCC is G12.25?
G12.25 (progressive spinal muscle atrophy) maps to CMS-HCC Category 190 (Amyotrophic Lateral Sclerosis and Other Motor Neuron Disease, Spinal Muscular Atrophy), commonly written as HCC 190, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 73 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 154.
Does G12.25 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, G12.25 adds a risk adjustment factor of about 1.175 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.628 to 3.642 depending on the payment segment). HCC 190 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 190 category page.
