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Neurological HCCs in CMS-HCC V28 (HCC 190-202)

The neurological group of the CMS-HCC V28 model holds 12 payment categories (HCC 190, 191, 192, 193, 195, 196, 197, 198, 199, 200, 201, 202): ALS, cerebral palsy, myasthenia gravis, MS, Parkinson disease, seizures and coma. 232 ICD-10-CM codes map to them in the payment year 2027 initial mapping. Community, non-dual, aged factors run from 0.245 (HCC 201) to 2.909 (HCC 195). 2 hierarchies rank HCC 191 > 192 and HCC 195 > 196, so a member is paid for at most one category in each chain.

Compiled from CMS files by the QuickIntell RCM Editorial Team · Data effective · Method: reference methodology · Report a data correction

Data currency: ICD-10-CM to HCC mapping: PY2027 initial ICD-10-CM mappings (dates of service 2026) (payment year 2027); CMS-HCC V28 model software: CMS-HCC V28 software V2826.115.T2 (PY2027 initial) (payment year 2027). Next CMS release: PY2028 advance notice (February 2027) and the PY2027 midyear final mapping (spring 2027).

Payment categories
12
Mapped ICD-10-CM codes
232
Factor range (CNA)
0.245 to 2.909
Hierarchies in the group
2
CMS hierarchy group "Neuro"

Categories and relative factors

Each factor is added to the member's demographic factors when the category is documented in the data collection year. Community, non-dual, aged (CNA) is the largest segment; the disabled (CND) and long-term institutional (INS) segments are estimated separately, which is why the same category is worth a different amount for each.

CMS-HCC V28 neurological categories with relative factors
HCCCategoryCodesCNACNDINS
HCC 190Amyotrophic Lateral Sclerosis and Other Motor Neuron Disease, Spinal Muscular Atrophy111.1751.7920.628
HCC 191Quadriplegic Cerebral Palsy10.8550.7430.000
HCC 192Cerebral Palsy, Except Quadriplegic90.3140.1290.000
HCC 193Chronic Inflammatory Demyelinating Polyneuritis and Multifocal Motor Neuropathy21.6921.4270.913
HCC 195Myasthenia Gravis with (Acute) Exacerbation12.9093.6331.837
HCC 196Myasthenia Gravis without (Acute) Exacerbation and Other Myoneural Disorders90.5160.6420.486
HCC 197Muscular Dystrophy210.4260.6320.292
HCC 198Multiple Sclerosis200.6470.9080.226
HCC 199Parkinson and Other Degenerative Disease of Basal Ganglia160.6150.5170.219
HCC 200Friedreich and Other Hereditary Ataxias; Huntington Disease170.2790.2080.000
HCC 201Seizure Disorders and Convulsions640.2450.1960.131
HCC 202Coma, Brain Compression/Anoxic Damage610.5430.2380.097

Hierarchy inside the group

The V28 hierarchy macro ranks related categories so that a member with codes in several of them is paid only for the higher-ranked one. Each category drops only the categories its own macro entry lists.

Read each chain left to right: every category drops every category to its right, so a member is paid for at most one category per chain.

  • HCC 191 (Quadriplegic Cerebral Palsy) > HCC 192 (Cerebral Palsy, Except Quadriplegic)
  • HCC 195 (Myasthenia Gravis with (Acute) Exacerbation) > HCC 196 (Myasthenia Gravis without (Acute) Exacerbation and Other Myoneural Disorders)

The macro also ranks some of these categories against categories in other groups:

Interaction terms that involve this group

V28 pays an extra factor when two condition groups are documented together, on top of each category's own factor. A blank cell means the segment carries no such term.

V28 interaction factors involving neurological categories
InteractionCNACNDINS
Disabled and neurological (institutional)0.154

ICD-10-CM code families

Where the mapped codes concentrate. A family with many codes is usually where specificity matters most: the category only counts when the documented diagnosis supports the exact code reported.

Three-character ICD-10-CM categories with the most codes in the neurological group
ICD-10-CM categoryMapped codes
G4058
R4043
G7121
P9114
G1111
G1211
G359
G708

Where these codes sat in V24

The payment year 2025 mapping lists the V24 and V28 category for the same codes. 18 codes in this group had no V24 payment category. The main V24 sources are below; the crosswalk report covers every category.

V24 categories behind the neurological V28 categories (PY2025 mapping)
V24 HCCV24 categoryCodes
79Seizure Disorders and Convulsions63
80Coma, Brain Compression/Anoxic Damage46
76Muscular Dystrophy20
78Parkinson's and Huntington's Diseases17
72Spinal Cord Disorders/Injuries15
75Myasthenia Gravis/Myoneural Disorders and Guillain-Barre Syndrome/Inflammatory and Toxic Neuropathy12

The CMS-HCC V24 vs V28 crosswalk shows the codes that lost or gained payment status across all categories.

Inpatient MS-DRGs that use these diagnoses

Appendix B of the v44 MS-DRG Definitions Manual names the DRGs whose logic uses each diagnosis. The same documentation supports the inpatient group and, for Medicare Advantage members, the risk score.

MS-DRGs whose logic lists the most neurological HCC codes
MS-DRGTitleShared codes
DRG 100Seizures with MCC62
DRG 101Seizures without MCC62
DRG 023Craniotomy with Major Device Implant or Acute Complex CNS Principal Diagnosis with MCC or Antineoplastic Implant or Epilepsy with Neurostimulator58
DRG 791Prematurity with Major Problems53
DRG 793Full Term Neonate with Major Problems53
DRG 056Degenerative Nervous System Disorders with MCC36
DRG 080Nontraumatic Stupor and Coma with MCC36
DRG 081Nontraumatic Stupor and Coma without MCC36

FY2027 code changes in this group

The October 1, 2026 ICD-10-CM update deleted no code mapped to this group, so its code lists carry into FY2027 unchanged until CMS posts a mapping for the new code set. The FY2027 code changes report lists every new and deleted code.

Where QuickIntell fits for neurological HCCs

An HCC counts only when the visit note supports it. QuickScribe captures the encounter documentation, and QuickCode supports qualified coder review and documentation clarification before diagnoses are submitted.

See QuickScribe for visit documentationSee QuickCode for coder reviewBook a meeting

Frequently asked questions

Which HCCs are in the V28 neurological group?

HCC 190 (Amyotrophic Lateral Sclerosis and Other Motor Neuron Disease, Spinal Muscular Atrophy, 11 codes, factor 1.175); HCC 191 (Quadriplegic Cerebral Palsy, 1 codes, factor 0.855); HCC 192 (Cerebral Palsy, Except Quadriplegic, 9 codes, factor 0.314); HCC 193 (Chronic Inflammatory Demyelinating Polyneuritis and Multifocal Motor Neuropathy, 2 codes, factor 1.692); HCC 195 (Myasthenia Gravis with (Acute) Exacerbation, 1 codes, factor 2.909); HCC 196 (Myasthenia Gravis without (Acute) Exacerbation and Other Myoneural Disorders, 9 codes, factor 0.516); HCC 197 (Muscular Dystrophy, 21 codes, factor 0.426); HCC 198 (Multiple Sclerosis, 20 codes, factor 0.647); HCC 199 (Parkinson and Other Degenerative Disease of Basal Ganglia, 16 codes, factor 0.615); HCC 200 (Friedreich and Other Hereditary Ataxias; Huntington Disease, 17 codes, factor 0.279); HCC 201 (Seizure Disorders and Convulsions, 64 codes, factor 0.245); HCC 202 (Coma, Brain Compression/Anoxic Damage, 61 codes, factor 0.543).

Which neurological HCC has the most mapped ICD-10-CM codes?

HCC 201, Seizure Disorders and Convulsions, with 64 codes in the PY2027 initial mapping; across the group the largest code families are G40 (58), R40 (43), G71 (21), P91 (14).

Where did the neurological codes sit in the V24 model?

In the PY2025 mapping, which carries both models, 223 code-to-category links point to this group; 18 of those codes had no V24 payment category. The main V24 sources were HCC 79 (Seizure Disorders and Convulsions, 63), HCC 80 (Coma, Brain Compression/Anoxic Damage, 46), HCC 76 (Muscular Dystrophy, 20).

Do neurological HCCs interact with other conditions in V28?

Yes. Disabled and neurological (institutional) adds 0.154 (long-term institutional only). Each term is added on top of the category factors when both conditions are documented.

Sources

Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-10. Verify against the primary file before billing or contracting decisions. The reference methodology explains how each figure is computed from these files.

Disclaimer

Factors, hierarchies and mappings are reproduced from the CMS risk adjustment model files as an operational reference. The group is a navigation aid built from the V28 hierarchy; CMS pays categories, not groups. Payment depends on the plan's base rate, normalization, the coding intensity adjustment and the enrollee's segment. Not legal, clinical or billing advice.

Found a figure that does not match the CMS file? Report a data correction with the CMS file and the value you expected; the request reaches the editorial team through the contact form.