Parkinson’s disease (PD) is a chronic and progressive neurodegenerative disorder that primarily affects the dopamine-producing neurons in a specific area of the brain. Scientists believe that the condition is caused by a combination of genetic and environmental factors. In many cases, an internist or family physician is the first to identify the condition, though patients typically consult a neurologist to confirm the diagnosis. Understanding the ICD-10 and CPT codes for Parkinson’s Disease (PD) is essential for family practice and neurology medical billing related to the condition.
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The World Health Organization reports that the prevalence of Parkinson’s disease (PD) has doubled over the past 25 years, with global estimates indicating more than 8.5 million individuals living with the condition in 2019. A study supported by the Parkinson’s Foundation in 2022 highlights a significant rise in U.S. diagnoses, revealing nearly 90,000 new cases annually—a sharp 50% increase from the previously estimated 60,000 diagnoses per year. By 2030, Parkinson’s cases in the U.S. are projected to exceed 1.2 million, according to the Foundation.
Diagnosing PD
Diagnosing PD, especially in its early stages, can be challenging. There are no specific lab or imaging tests that definitively diagnose PD. The condition is diagnosed clinically, meaning it is based on an individual’s medical history, symptoms, and physical examination. Symptoms of this motor system disorder include:
- Tremors in the hands, arms, legs, jaw and face
- Slowness of movement
- Rigidity of the limbs and trunk
- Impaired balance and coordination
Tests like magnetic resonance imaging (MRI) of the brain, dopamine transporter scans (DaT scans), or blood work may be used to support the diagnosis or rule out other medical conditions have symptoms similar to PD.
ICD-10 Codes for Parkinson’s Disease
The primary ICD-10 code for Parkinson’s Disease is G20. It applies to
- G20 – This code indicates the presence of PD through clinical evaluation and diagnostic testing for Parkinson’s Disease Diagnosis. G20 is applicable to a number of types of Parkinson’s disease, including:
- Hemiparkinsonism
- Idiopathic Parkinsonism or Parkinson’s disease
- Paralysis agitans
- Parkinsonism or Parkinson’s disease NOS, and
- Primary Parkinsonism or Parkinson’s disease
In 2023, ICD-10 code G20 expanded into the following five codes:
- G20.A1 (Parkinson’s disease without dyskinesia, without mention of fluctuations),
- G20.A2 (Parkinson’s disease without dyskinesia, with fluctuations),
- G20.B1 (Parkinson’s disease with dyskinesia, without mention of fluctuations),
- G20.B2 (Parkinson’s disease with dyskinesia, with fluctuations),
- G20.C (Parkinsonism, unspecified).
AAPC instructs using additional code, if applicable, to identify:
- dementia with anxiety (F02.84, F02.A4, F02.B4, F02.C4)
- dementia with behavioral disturbance (F02.81-, F02.A1-, F02.B1-, F02.C1-)
- dementia with mood disturbance (F02.83, F02.A3, F02.B3, F02.C3)
- dementia with psychotic disturbance (F02.82, F02.A2, F02.B2, F02.C2)
- dementia without behavioral disturbance (F02.80, F02.A0, F02.B0, F02.C0)
- mild neurocognitive disorder due to known physiological condition (F06.7-)
- G21: Secondary Parkinsonism – This code is used to classify the Parkinson’s Disease diagnosis when Parkinsons-like symptoms are caused by other factors, such as medications, toxins, or other medical conditions. Related codes:
- G21.0: Malignant neuroleptic syndrome, a life-threatening condition that can be caused by certain drugs. Symptoms include high fever, sweating, confusion, and stiffness.
- G21.1: Other drug-induced secondary parkinsonism
- G21.2: Secondary parkinsonism due to other external agents
- G21.3: Postencephalitic parkinsonism
- G21.4: Vascular parkinsonism
- G21.8: Other secondary parkinsonism
- G21.9: Secondary parkinsonism, unspecified
- G22: Parkinsonism in diseases classified elsewhere
Notations, inclusions and/or exclusions that are specific to these ICD 10 codes need to be checked before using them.
CPT Codes for Tests that Support PD Diagnosis
PD is primarily a clinical diagnosis. However, tests that support the diagnosis or rule out other conditions may involve the following CPT codes:
- Imaging Studies
MRI of the Brain
- 70551: Without contrast
- 70552: With contrast:
- 70553: Without and with contrast
DaTscan (Dopamine Transporter Scan)
- 78803: Radiopharmaceutical administration
- 78607: SPECT imaging for brain
- A9592 (HCPCS code): Radiopharmaceutical supply (e.g., I-123 ioflupane)
- Electrophysiological Tests
Nerve conduction studies or EMG are used to rule out other neurological conditions.
- 95907: Nerve conduction study (1-2 studies)
- 95860 Needle EMG, 1 extremity with or without related paraspinal areas
- Laboratory Tests
While there are no definitive blood tests for PD, general tests may be performed to exclude other conditions:
- 84443: Thyroid function tests (e.g., TSH)
- 82607: Vitamin B12 levels
- 80053: Comprehensive metabolic panel (CMP)
These codes depend on the services provided and documentation. Verifying specific payer requirements and guidelines is essential for correct usage.
E/M Coding
When billing for an office visit related to Parkinson’s disease, the appropriate E/M code (based on the level of complexity of the visit) would be used alongside the G20 diagnosis code:
New Patient Office Visit
99202: Straightforward MDM or 15–29 minutes of total time.
99203: Low complexity MDM or 30–44 minutes of total time.
99204: Moderate complexity MDM or 45–59 minutes of total time.
99205: High complexity MDM or 60–74 minutes of total time.Established Patient Office Visit
99211: Minimal or no MDM, typically 5–10 minutes (e.g., nurse visit).
99212: Straightforward MDM or 10–19 minutes of total time.
99213: Low complexity MDM or 20–29 minutes of total time.
99214: Moderate complexity MDM or 30–39 minutes of total time.
99215: High complexity MDM or 40–54 minutes of total time.Neurology billing and coding can be challenging due to the complexity of neurological disorders, documentation requirements, and regulatory compliance. It’s essential to clearly document the purpose of the visit (e.g., new symptoms, medication management, coordination of care). If total time spent is the primary basis for the code, include documentation of face-to-face and non-face-to-face time spent on patient care. Add appropriate modifiers when needed (e.g., -25 for separately identifiable services performed on the same day). The documentation must align with the chosen code and payer guidelines.
Reach Out to an Expert
Partnering with a neurology medical billing company can ensure valuable support to optimize revenue cycle management while ensuring compliance with complex billing and coding regulations. Neurology procedures and tests often require prior authorizations, which can be time-consuming. Billing companies employ insurance verification specialists who efficiently manage this process, ensuring timely approvals. Additionally, these companies rely on AAPC-certified coders with expertise in neurology to minimize coding errors, ensuring accurate claims submissions. This reduces the risk of denials, payment delays, and insurance coverage complications.
Ensure accurate coding and timely reimbursements for Parkinson’s care with our neurology billing services!
Meghann Drella possesses a profound understanding of ICD-10-CM and CPT requirements and procedures, actively participating in continuing education to stay abreast of any industry changes.
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