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Provider Manual

Risk Adjustment - Neurological conditions

Last Updated on June 17, 2019

Neurological Conditions and Hierarchical Condition Category (HCC) Coding

Risk adjustment models are designed to assign values that help identify patients likely to incur higher than average costs of care.  There are multiple, chronic, neurologic conditions that have long term implications on an individual’s health care needs and costs.  Many of these conditions are associated with a HCC code and add a risk factor coefficient to a patients risk score.  The following information is intended to provide details needed to accurately document and code these conditions, using ICD 10 coding guidelines.  

Alzheimer’s disease (ICD 10 code G30.0)

The diagnosis of Alzheimer’s disease is not associated with a HCC code.  However, it is possible that some of the associated behavioral symptoms might be.  In order to accurately assign an Alzheimer disease code, please include the following details when documenting and coding about your patient’s condition;

  • Associated with delirium, or behavioral disturbance (be specific)
  • Early onset/late onset

Cerebral palsy (ICD 10 code G80)

Clarify the type of cerebral palsy a patient has when documenting and coding on the condition.   Document if the patient’s condition is;

  • Athetoid, ataxic, spastic or mixed
  • Diplegic, hemiplegic, quadraplegic

Cerebral Vascular Disease (CVD)

The table below outlines the CVD ICD – 10 codes and the information that is needed to accurately assign a diagnosis code.

ICD - 10 codes Code description Information needed in documentation
I60 – I62 Non-traumatic intracranial hemorrhage (i.e., spontaneous subarachnoid, intracerebral, or subdural hemorrhages)
  • Location/source
  • Laterality
I63 Cerebral infarction
  • Cause of infarct–thrombosis or embolism
  • Location
  • Laterality
I65 - I66
(do not risk adjust)
Occlusion and stenosis of cerebral or precerebral vessels without infarction
  • Location
  • Laterality
I67 – I68 Other cerebrovascular diseases Indicate the specific condition, such as cerebral aneurysm, atherosclerosis or arteritis, etc. *Note that nonruptured dissection of cerebral arteries is the only code in this code set that risk adjusts.
I69 Sequelae of cerebrovascular disease (late effect)
  • Type of event that caused the sequelae
  • What is the sequelae & what is affected
  • Monoplegia/hemiplegia
  • Upper /lower extremity
  • Laterality
  • Dominant/non-dominant or unknown dominant side affected
    • Ataxia, apraxia, dysphagia, facial weakness and speech and language deficits associated with CVD do not risk adjust

When a patient has a history of CVD without neurological deficits, report the history of transient ischemic attack and cerebral infarction without residual deficits code (Z86.73).

Epilepsy (ICD 10 G40 codes)

There are multiple ICD 10 codes associated with epilepsy.  In order to accurately diagnose a patient’s condition, please document and consider the following in diagnostic code selection;

Is the patients epilepsy

  • Focal, partial or  generalized
  • Intractable or non-intractable
  • With or without  status epilepticus
  • Idiopathic or external cause
  • Does the patient have an epileptic syndrome, such as Lennox-Gastaut, Laundau Kleffner syndrome, or infantile spasms
  • Does the patient have febrile convulsions or post traumatic seizures

Hydrocephalus (ICD 10 code G91)

Document and code the type of hydrocephalus;

  • Communicating
  • Obstructive
  • Normal pressure
  • Post traumatic
  • Associated with another condition, such as congenital syphilis or neoplasm

Note that within this code set; only congenital hydrocephalus is associated with a HCC code.

Multiple Sclerosis (ICD 10 code G35) – is associated with a HCC code.

Myasthenia gravis (ICD 10 code G70.x)

Specify if the condition is;

  • With or without acute exacerbation
  • Due to a toxic agent – document what that toxin is

Parkinson’s disease or Secondary Parkinson’s disease (ICD 10 codes G20 – G21.9)

Parkinson’s disease is a HCC diagnosis, whether the condition is idiopathic, drug induced or a result of infectious or other external agents.

Neuropathy (ICD 10 G60 – G65 codes)

There are multiple types of neuropathy.  Some, but not all neuropathies are associated with a HCC code.  Be sure to include a description of the patient’s symptoms, along with the type of neuropathy the patient has, to support the neuropathy code you submit on your claim for the patient’s service.  The neuropathies listed below are associated with a HCC diagnosis;

  • Inflammatory polyneuropathy
  • Polyneuropathy that is due to alcohol, toxic agents, critical illness, radiation or drug induced
  • Polyneuropathy in other diseases - document and code the other disease, such as amyloidosis, endocrine disease, metabolic disease, neoplasm or nutritional deficiencies

Hemiplegia & hemiparesis (ICD 10 G81 codes)

This category is to be used only when hemiplegia (complete) (incomplete) is reported without further specification, or is stated to be old or longstanding but of unspecified cause. The category is also for use in multiple coding to identify these types of hemiplegia resulting from any cause.  When documenting and coding on this condition, include the following details;

  • Flaccid/spastic
  • Right/left side affected
  • Dominant or nondominant side affected

Para-plegia/paresis & Quadra-plegia/paresis (ICD 10 G82 codes)

This category is to be used only when the listed conditions are reported without further specification, or are stated to be old or longstanding but of unspecified cause. The category is also for use in multiple coding to identify these conditions resulting from any cause.  Include the following details in your documentation related to these conditions;

  • Paraplegia
    • Complete/incomplete
    • Quadraplegia
      • Complete/incomplete
      • Level of cervical injury


Brenda Anderson
Revenue Management Educator
Security Health Plan 
Telephone: 715-221-9598

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