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HCC 201: Seizure Disorders and Convulsions

HCC 201, Seizure Disorders and Convulsions, is one of the 115 payment categories in the CMS-HCC V28 model. 64 ICD-10-CM codes map to it in the payment year 2027 mapping, and a documented diagnosis in the category adds a relative factor of 0.245 to the risk score of a community, non-dual, aged beneficiary (0.196 disabled, 0.131 institutional). It sits at the top of its hierarchy, so no other category overrides it.

QuickIntell editorial content · Legacy registry date · Review not verified

Data effective
Data currency: ICD-10-CM to HCC mapping PY2027 initial (effective dates of service 2026, payment year 2027); CMS-HCC V28 model software V2826.115.T2 (effective payment year 2027). Next CMS release: PY2027 midyear final mapping (spring 2027) and PY2028 proposed model (February 2027).
Mapped ICD-10-CM codes
64
Factor, community non-dual aged
0.245
Factor, institutional
0.131
Hierarchy
Top of hierarchy

Relative factors by segment

Each segment is a separate regression; the factor is added to the beneficiary's demographic factors and other categories, then normalized and reduced by the coding intensity adjustment before it meets the plan's base rate. A factor of 1.000 equals the expected cost of an average beneficiary.

CMS-HCC V28 relative factors for HCC 201 by model segment
SegmentModel codeRelative factor
Community, non-dual, agedCNA_HCC2010.245
Community, non-dual, disabledCND_HCC2010.196
Community, full-benefit dual, agedCFA_HCC2010.233
Community, full-benefit dual, disabledCFD_HCC2010.170
Community, partial-benefit dual, agedCPA_HCC2010.245
Community, partial-benefit dual, disabledCPD_HCC2010.202
Long-term institutionalINS_HCC2010.131

Hierarchy

HCC 201 is not part of a hierarchy: it is paid whenever a mapped diagnosis is documented, independently of the beneficiary's other categories.

ICD-10-CM codes that map to HCC 201

64 codes map to this category in the PY2027 initial mapping, concentrated in the G40 (58), R56 (4), G93 (1), P90 (1) code families. Descriptions are the CMS mapping descriptions for the FY2026 code set; a code that is deleted or split in the October code update stays valid for dates of service before the change.

ICD-10-CM codes mapped to HCC 201 in the CMS PY2027 initial mapping
ICD-10-CMDescription
G40001Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, not intractable, with status epilepticus
G40009Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, not intractable, without status epilepticus
G40011Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, intractable, with status epilepticus
G40019Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, intractable, without status epilepticus
G40101Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable, with status epilepticus
G40109Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable, without status epilepticus
G40111Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, intractable, with status epilepticus
G40119Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, intractable, without status epilepticus
G40201Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, not intractable, with status epilepticus
G40209Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, not intractable, without status epilepticus
G40211Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, intractable, with status epilepticus
G40219Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, intractable, without status epilepticus
G40301Generalized idiopathic epilepsy and epileptic syndromes, not intractable, with status epilepticus
G40309Generalized idiopathic epilepsy and epileptic syndromes, not intractable, without status epilepticus
G40311Generalized idiopathic epilepsy and epileptic syndromes, intractable, with status epilepticus
G40319Generalized idiopathic epilepsy and epileptic syndromes, intractable, without status epilepticus
G40401Other generalized epilepsy and epileptic syndromes, not intractable, with status epilepticus
G40409Other generalized epilepsy and epileptic syndromes, not intractable, without status epilepticus
G40411Other generalized epilepsy and epileptic syndromes, intractable, with status epilepticus
G40419Other generalized epilepsy and epileptic syndromes, intractable, without status epilepticus
G4042Cyclin-Dependent Kinase-Like 5 Deficiency Disorder
G40501Epileptic seizures related to external causes, not intractable, with status epilepticus
G40509Epileptic seizures related to external causes, not intractable, without status epilepticus
G40801Other epilepsy, not intractable, with status epilepticus
G40802Other epilepsy, not intractable, without status epilepticus
G40803Other epilepsy, intractable, with status epilepticus
G40804Other epilepsy, intractable, without status epilepticus
G40811Lennox-Gastaut syndrome, not intractable, with status epilepticus
G40812Lennox-Gastaut syndrome, not intractable, without status epilepticus
G40813Lennox-Gastaut syndrome, intractable, with status epilepticus
G40814Lennox-Gastaut syndrome, intractable, without status epilepticus
G40821Epileptic spasms, not intractable, with status epilepticus
G40822Epileptic spasms, not intractable, without status epilepticus
G40823Epileptic spasms, intractable, with status epilepticus
G40824Epileptic spasms, intractable, without status epilepticus
G40833Dravet syndrome, intractable, with status epilepticus
G40834Dravet syndrome, intractable, without status epilepticus
G40841KCNQ2-related epilepsy, not intractable, with status epilepticus
G40842KCNQ2-related epilepsy, not intractable, without status epilepticus
G40843KCNQ2-related epilepsy, intractable, with status epilepticus
G40844KCNQ2-related epilepsy, intractable, without status epilepticus
G4089Other seizures
G40901Epilepsy, unspecified, not intractable, with status epilepticus
G40909Epilepsy, unspecified, not intractable, without status epilepticus
G40911Epilepsy, unspecified, intractable, with status epilepticus
G40919Epilepsy, unspecified, intractable, without status epilepticus
G40A01Absence epileptic syndrome, not intractable, with status epilepticus
G40A09Absence epileptic syndrome, not intractable, without status epilepticus
G40A11Absence epileptic syndrome, intractable, with status epilepticus
G40A19Absence epileptic syndrome, intractable, without status epilepticus
G40B01Juvenile myoclonic epilepsy, not intractable, with status epilepticus
G40B09Juvenile myoclonic epilepsy, not intractable, without status epilepticus
G40B11Juvenile myoclonic epilepsy, intractable, with status epilepticus
G40B19Juvenile myoclonic epilepsy, intractable, without status epilepticus
G40C01Lafora progressive myoclonus epilepsy, not intractable, with status epilepticus
G40C09Lafora progressive myoclonus epilepsy, not intractable, without status epilepticus
G40C11Lafora progressive myoclonus epilepsy, intractable, with status epilepticus
G40C19Lafora progressive myoclonus epilepsy, intractable, without status epilepticus
G9345Developmental and epileptic encephalopathy
P90Convulsions of newborn
R5600Simple febrile convulsions
R5601Complex febrile convulsions
R561Post traumatic seizures
R569Unspecified convulsions

Where these codes sat in the V22 model

The V28 recalibration renumbered and regrouped categories; this table shows which legacy V22 categories the same ICD-10 codes belonged to, which is the quickest way to reconcile a V22-era HCC gap list with the current model.

V22 categories that the HCC 201 codes mapped to
V22 HCCCodes
7963

Capturing and defending the category

A category counts for a payment year when a mapped diagnosis is documented at least once during the data collection year by an acceptable provider type at a face-to-face or audio-video encounter, and when the note shows the condition was monitored, evaluated, assessed or treated. Chronic conditions do not carry forward: a category that is not re-documented in the year drops out of the score, which is why annual wellness visits and problem-list reconciliation are where most recapture happens. Risk adjustment data validation audits sample enrollees and ask for the medical record behind each submitted category; an unsupported category is removed and, under the extrapolation rules, the error rate is applied across the contract. The QuickIntell risk adjustment product surfaces suspected and unsupported categories from the chart, and the HCC hub lists every V28 category with its factor and code count.

Frequently asked questions

Which ICD-10 codes map to HCC 201?

64 ICD-10-CM codes map to HCC 201 in the CMS PY2027 initial mapping, for example G40001 Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, not intractable, with status epilepticus; G40009 Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, not intractable, without status epilepticus; G40011 Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, intractable, with status epilepticus; G40019 Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, intractable, without status epilepticus. The full list is on this page; a code counts only when it is documented at a face-to-face or video encounter in the data collection year and supported by the record.

How much does HCC 201 add to a risk score?

The V28 relative factor for HCC 201 is 0.245 for a community, non-dual, aged beneficiary, 0.233 for full-benefit dual aged, 0.196 for non-dual disabled and 0.131 for long-term institutional members. A factor of 1.000 equals the expected annual cost of an average beneficiary, so the category's share of the payment follows the plan's base rate for that segment.

Does HCC 201 count together with related categories?

HCC 201 is not part of a hierarchy, so it is paid whenever it is documented regardless of which other categories the beneficiary has.

What has to be documented for HCC 201 to be valid?

The diagnosis must be recorded by an acceptable provider type during a face-to-face or audio-video encounter in the service year, with the note showing that the condition was monitored, evaluated, assessed or treated. Risk adjustment data validation audits recover payment for categories the record does not support, so the code on the claim and the assessment in the note must match.

Sources

Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-02. Verify against the primary file before billing or contracting decisions.

Disclaimer

Relative factors and mappings are reproduced from the CMS risk adjustment model files as an operational reference. Payment depends on the plan's base rate, normalization, the coding intensity adjustment and the enrollee's segment. Not legal, clinical or billing advice.