2021 ICD-10-CM Code G21.8

Other secondary parkinsonism

Version 2021

Valid for Submission

G21.8 is a billable diagnosis code used to specify a medical diagnosis of other secondary parkinsonism. The code G21.8 is valid during the fiscal year 2021 from October 01, 2020 through September 30, 2021 for the submission of HIPAA-covered transactions.

The ICD-10-CM code G21.8 might also be used to specify conditions or terms like infection causing parkinsonism, parkinsonism co-occurrent and due to acute infection, parkinsonism due to and following injury of head, parkinsonism due to hereditary spastic paraplegia, parkinsonism due to heredodegenerative disorder , parkinsonism due to human immunodeficiency virus infection, etc.

ICD-10:G21.8
Short Description:Other secondary parkinsonism
Long Description:Other secondary parkinsonism

Code Classification

Index to Diseases and Injuries

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for the code G21.8 are found in the index:

Approximate Synonyms

The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

Clinical Information

Convert G21.8 to ICD-9 Code

The General Equivalency Mapping (GEM) crosswalk indicates an approximate mapping between the ICD-10 code G21.8 its ICD-9 equivalent. The approximate mapping means there is not an exact match between the ICD-10 code and the ICD-9 code and the mapped code is not a precise representation of the original code.

Information for Patients


Parkinson's Disease

Also called: Paralysis agitans, Shaking palsy

Parkinson's disease (PD) is a type of movement disorder. It happens when nerve cells in the brain don't produce enough of a brain chemical called dopamine. Sometimes it is genetic, but most cases do not seem to run in families. Exposure to chemicals in the environment might play a role.

Symptoms begin gradually, often on one side of the body. Later they affect both sides. They include

As symptoms get worse, people with the disease may have trouble walking, talking, or doing simple tasks. They may also have problems such as depression, sleep problems, or trouble chewing, swallowing, or speaking.

There is no lab test for PD, so it can be difficult to diagnose. Doctors use a medical history and a neurological examination to diagnose it.

PD usually begins around age 60, but it can start earlier. It is more common in men than in women. There is no cure for PD. A variety of medicines sometimes help symptoms dramatically. Surgery and deep brain stimulation (DBS) can help severe cases. With DBS, electrodes are surgically implanted in the brain. They send electrical pulses to stimulate the parts of the brain that control movement.

NIH: National Institute of Neurological Disorders and Stroke


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Code History

  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016 (First year ICD-10-CM implemented into the HIPAA code set)