Diagnosis of Parkinson’s Disease (PD) and Medical Billing

by | Published on Mar 19, 2015 | Resources, Articles | 0 comments

Share this:

According to the American Parkinson’s Disease Association, approximately 60,000 people are newly diagnosed with Parkinson’s Disease (PD) each year. Accurate diagnosis of this disease is very important as researches have shown there is higher morbidity rate for this disease when associated with conditions in the mental, psychiatric, nervous, gastrointestinal, musculoskeletal, and genitourinary systems among others.

Error-free documentation is vital from the point of view of quality care provision and follow up for the patient. But this is challenging as PD is still diagnosed on clinical grounds. Physicians providing treatment for this condition should ensure accurate diagnostic and procedure codes in their medical claims for a smooth billing process.

Why Diagnosing PD Is Challenging

Typically, PD is diagnosed with four main motor symptoms including shaking or tremor, slowness of movement (bradykinesia), stiffness or rigidity of the arms, legs or trunk and difficulty in balancing and possible falls (postural instability). However, non-motor symptoms are probably present early on, before and after the diagnosis, which can provide important information about the progression of the disease. This June, a study was published in Neurology, the Official Journal of the American Academy of Neurology regarding the clinical diagnostic accuracy of PD. According to the lead author of this study, the clinical signs of PD such as tremor, rigidity and others are not specific to the disease, but may also be symptoms of many other neurodegenerative disorders. There is higher probability of making a correct diagnosis if you follow a patient and monitor the response to medication for a longer period.

The researchers collected data from the Arizona Study of Aging and Neurodegenerative Disorders in order to assess the accuracy of clinical diagnosis of PD, using neuropathologic diagnosis as the gold standard. Two clinical diagnostic confidence levels were used for the study, Possible PD or PossPD (defined as 2 of the 3 cardinal signs of PD (rest tremor, bradykinesia, rigidity), no symptomatic cause, symptoms or signs present for 5 years or less, and never treated or not clearly responsive to dopaminergic therapy) and Probable PD or ProbPD (defined as 2 of the 3 cardinal signs, no symptomatic cause, and responsive to medications). There were in all 232 patients with Parkinsonism during the first visit among whom 34 had PossPD, 97 had ProbPD and 101 had other types of Parkinsonism and here are the end results of the study.

  • In case of PossPD (never treated or not clearly responsive), only 9 (26%) of 34 patients had neuropathologically confirmed PD during the first visit.
  • In the case of ProbPD (responsive to medication), PD was confirmed in 72 (88%) of 82 ProbPD cases with symptoms for 5 years or longer and in 8 (53%) of 15 patients with symptoms present for less than 5 years. This indicates that longer disease duration improved diagnostic accuracy.
  • With the final diagnosis at the time of death, PD was confirmed in 91 (85%) of 107 ProbPD cases.

The clinical variables that improved the diagnostic accuracy as per the study were medication response, dyskinesias, hyposomia and motor fluctuations.

Diagnostic Codes for PD


  • 332: Parkinson’s disease
  • 332.0: Paralysis agitans
  • 332.1: Secondary parkinsonism


  • G20: Parkinson’s disease
  • G21.11: Neuroleptic induced parkinsonism
  • G21.19: Other drug induced secondary parkinsonism
  • G21.8: Other secondary parkinsonism

Evaluation and Management (E/M) Codes for Billing

Apart from diagnostic codes, E/M codes are essential for physicians to obtain reimbursement for clinical visits for PD treatment.

New HCPCS Code

Under the 2014 Medicare hospital outpatient prospective payment system (OPPS) Final Rule, all clinic visits are paid at a single rate according to the relevant Ambulatory Payment Classification (APC) code instead of reimbursing on the basis of the acuity of the patients or the types of hospital/nursing services rendered. Following the rule, CPT codes 99201-99205 for new patient visit and 99211-99215 for established patient visit are replaced with HCPCS code G0463 which is payable under APC 0634.

Codes for Prolonged Service

The codes for prolonged service are used when healthcare professionals provide prolonged service beyond the usual service. This service is provided in the outpatient or inpatient setting and it should be reported in addition to the designated evaluation and management service at any level and services provided at the same session, if any.

Prolonged Service with Direct Patient Contact

  • 99354: Prolonged service in the office or other outpatient setting requiring direct patient contact beyond the usual service; first hour
  • 99355: Each additional 30 minutes
  • 99356: Prolonged service in the inpatient or observation setting, requiring unit/floor time beyond the usual service; first hour
  • 99357: each additional 30 minutes

Prolonged Service without Direct Patient Contact

  • 99358: Prolonged evaluation and management service before and/or after direct patient care; first hour (not an Add-on code)
  • 99359: each additional 30 minutes

Ensure that the prolonged services rendered are all face-to-face since Medicare and Medicare Advantage Plans do not recognize any kind of prolonged services that are not 100% physician/patient face to face. The codes 99354, 99356 and 99358 should not be reported for less than 30 minutes total duration while the codes 99355, 99357 and 99359 should not be reported for less than 15 minutes total duration. The total duration does not have to be continuous. In case of ‘Prolonged Service without Direct Patient Contact’, it may be reported for a different date of service instead of the primary service to which it is related. The threshold times must be met according to the E/M code reported.  The start/stop times should be included in the documentation along with a summary that indicates how the prolonged service was rendered.

Use modifier 25 if there is a same day separate procedure, which means an E/M visit and a procedure with separate documentation (for example, botulinum injection).

Outsource Strategies International.

Being an experienced medical billing and coding company in the U.S., OSI is dedicated to staying abreast of the latest industry guidelines. Our services provide comprehensive support for the success of your practice.

More from This Author

Related Posts