• Change From Baseline in Movement Disorders Society -Unified Parkinson's Disease Rating Scale (MDS-UPDRS) [ Time Frame: Baseline to Study Day 60 ]
  MDS-UPDRS: 4-part assessment of the multiple clinical disabilities of Parkinson's Disease. Part I (13 items; Score 0-52) examines non-motor experiences, Part II (13 items; Score 0-52) examines motor experiences, Part III (33 items; Score 0-132) examines the cardinal motor disabilities and Part IV (6 items; Score 0-24) examines motor complications. Each Part has 0-4 ratings, where 0 (no problems) to 4 (severe problems) and scores for each part are summed to calculate the total score which ranges from 0-260. Higher scores represent worse outcomes for each part and total score.
• Change From Baseline in Parkinson's Disease Questionnaire (PDQ-39) Scores [ Time Frame: Baseline to Study Day 60 ]
  PDQ-39 is a patient-reported outcome designed to address aspects of functioning and well-being for those affected by PD. Each of the 39 items is rated using a 5 point Likert scale with 0 for never having difficulties/problems and 4 for always having difficulties/problems. The sum score of the 39 items will be calculated and used for analysis, with scores ranging from 0-156. Higher scores indicate worse outcomes.
• Change From Baseline in Montreal Cognitive Assessment (MoCA) Total Score. [ Time Frame: Baseline to Study Day 60 ]
  MoCA is a 30-point, 1-page test designed to assess several cognitive domains, including visuospatial abilities (5 points), naming (3 points), attention (6 points), language (3 points), abstraction (2 points), delayed recall (5 points), and orientation to time and place (6 points). The total score ranges from 0 to 30, with higher scores indicating better performances.
• Treatment Satisfaction Questionnaire for Medication (TSQM-9) Scores [ Time Frame: Study Day 60 ]
  TSQM-9 consists of 9 questions to assess patients' satisfaction with medication using a range of responses from 1 (extremely dissatisfied) to (7 extremely satisfied). This patient reported outcome provides scores on three parts: effectiveness, convenience, and global satisfaction. The sum of the 9-questions will be calculated and used for analysis. The total score ranges from 0 to 63, with higher scores indicating better treatment satisfaction.
• Clinical Global Impression of Change (CGI-C) [ Time Frame: Study Day 60 ]
  CGI-C is a 7-point scale depicting a Principal Investigator or certified Health Care Professional designee rating of the patient's overall improvement using a range of responses from a minimum of 1 (very much improved) to a maximum of 7 (very much worse).
• Patient Global Impression of Change (PGI-C) [ Time Frame: Study Day 60 ]
  PGI-C is a 7-point scale depicting a patient's rating of overall improvement using a range of responses from 1 (very much improved) to 7 (very much worse).

• Change From Baseline in Movement Disorders Society -Unified Parkinson's Disease Rating Scale (MDS-UPDRS) [ Time Frame: Baseline to Study Day 60 ]
  MDS-UPDRS is a 4-part assessment of the multiple clinical disabilities of Parkinson's Disease. Part I (13 items) examines non-motor experiences of daily living, Part II (13 items) examines motor experiences of daily living, Part III (33 items) examines the cardinal motor disabilities of PD, and Part IV (6 items) examines motor complications. Each item has 0-4 ratings, where 0 (normal) to 4 (severe) and scores for each part is summed to calculate the total scores. The total score ranges from 0 to 260, with higher scores indicating worse outcomes.
• Change From Baseline in Parkinson's Disease Questionnaire (PDQ-39) Scores [ Time Frame: Baseline to Study Day 60 ]
  PDQ-39 is a patient-reported outcome designed to address aspects of functioning and well-being for those affected by PD. Each of the 39 items is rated using a 5 point Likert scale, with 0 for never having difficulties/problems and 4 for always having difficulties/problems. The sum score of the 39 items will be calculated and used for analysis, with the maximum score of 156. Higher scores indicate worse outcomes.
• Change From Baseline in Montreal Cognitive Assessment (MoCA) Total Score. [ Time Frame: Baseline to Study Day 60 ]
  MoCA is a 30-point, 1-page test designed to assess several cognitive domains, including visuospatial abilities (5 points), naming (3 points), attention (6 points), language (3 points), abstraction (2 points), delayed recall (5 points), and orientation to time and place (6 points). The total score ranges from 0 to 30, with higher scores indicating better performances.
• Change from baseline in Treatment Satisfaction Questionnaire for Medication (TSQM-9) scores [ Time Frame: Baseline to Study Day 60 ]
  TSQM-9 consists of 9 questions to assess patients' satisfaction with medication using a range of responses from 1 (extremely dissatisfied) to (7 extremely satisfied). This patient reported outcome provides scores on three parts: effectiveness, convenience, and global satisfaction. The sum of the 9-questions will be calculated and used for analysis. The total score ranges from 0 to 30, with higher scores indicating better treatment satisfaction.
• Clinical Global Impression of Change (CGI-C) [ Time Frame: Baseline to Study Day 60 ]
  CGI-C is a 7-point scale depicting a Principal Investigator or certified Health Care Professional designee rating of the patient's overall improvement using a range of responses from 1 (very much improved) through to 7 (very much worse).
• Patient Global Impression of Change (PGI-C) [ Time Frame: Baseline to Study Day 60 ]
  PGI-C is a 7-point scale depicting a patient's rating of overall improvement using a range of responses from 1 (very much improved) to 7 (very much worse).

• Change from baseline in Movement Disorders Society -Unified Parkinson's Disease Rating Scale [ Time Frame: Baseline to treatment extension period visits on study day 90 and day 180 ]
  MDS-UPDRS is a 4-part assessment of the multiple clinical disabilities of Parkinson's Disease. Part I (13 items) examines non-motor experiences of daily living, Part II (13 items) examines motor experiences of daily living, Part III (33 items) examines the cardinal motor disabilities of PD, and Part IV (6 items) examines motor complications. Each item has 0-4 ratings, where 0 (normal) to 4 (severe) and scores for each part is summed to calculate the total scores. The total score ranges from 0 to 260, with higher scores indicating worse outcomes.
• Change from baseline in Parkinson's Disease Questionnaire (PDQ-39) scores [ Time Frame: Baseline to treatment extension period visits on study day 90 and day 180 ]
  PDQ-39 is a patient-reported outcome designed to address aspects of functioning and well-being for those affected by PD. Each of the 39 items is rated using a 5 point Likert scale, with 0 for never having difficulties/problems and 4 for always having difficulties/problems. The sum score of the 39 items will be calculated and used for analysis, with the maximum score of 156. Higher scores indicate worse outcomes.
• Change from baseline in Montreal Cognitive Assessment (MoCA) total score. [ Time Frame: Baseline to treatment extension period visits on study day 180 ]
  MoCA is a 30-point, 1-page test designed to assess several cognitive domains, including visuospatial abilities (5 points), naming (3 points), attention (6 points), language (3 points), abstraction (2 points), delayed recall (5 points), and orientation to time and place (6 points). The total score ranges from 0 to 30, with higher scores indicating better performances.
• Change from baseline in Treatment Satisfaction Questionnaire for Medication (TSQM-9) [ Time Frame: Baseline to study day 30; treatment extension period visits on day 90, day 120 and day 180 ]
  TSQM-9 consists of 9 questions to assess patients' satisfaction with medication using a range of responses from 1 (extremely dissatisfied) to (7 extremely satisfied). This patient reported outcome provides scores on three parts: effectiveness, convenience, and global satisfaction. The sum of the 9-questions will be calculated and used for analysis. The total score ranges from 0 to 30, with higher scores indicating better treatment satisfaction.
• Clinical Global Impression of Change (CGI-C) [ Time Frame: Baseline to treatment extension period visits on study day 90 and day 180 ]
  CGI-C is a 7-point scale depicting a Principal Investigator or certified Health Care Professional designee rating of the patient's overall improvement using a range of responses from 1 (very much improved) through to 7 (very much worse).
• Patient Global Impression of Change (PGI-C) [ Time Frame: Baseline to treatment extension period visits on study day 90 and day 180 ]
  PGI-C is a 7-point scale depicting a patient's rating of overall improvement using a range of responses from 1 (very much improved) to 7 (very much worse).

This Phase IV, multicenter, prospective, observational study to evaluate clinician-reported outcomes and patient-reported outcomes related to motor and non-motor symptoms, health status, quality of life and treatment satisfaction in PD patients who have been newly prescribed XADAGO according to Package Insert indication.

This study also will gather "real world" data from a PD population in the US regarding their overall experience and degree of satisfaction with the use of XADAGO as an add-on treatment to their L-dopa regimen. Treatment experience will be captured using patient self-rating assessments as well as clinician ratings on assessments.

Inclusion Criteria:

1. Patient (and Care Partner, if required per Inclusion Criterion 6) is able to understand and provide signed informed consent and HIPAA authorization in English.
2. Patient with diagnosis of idiopathic PD (all stages).
3. Independent of the study, clinician's and patient's choice of treatment is XADAGO in accordance with the Package Insert indication.
4. Patient is willing and able to participate in the study and complete study-related assessments for 2 months and, patients can continue for an optional 4-month study extension.
5. Patient has access to an electronic device for the interim completion of PROs.
6. Patient has an available Care Partner who is able and willing to assist with clinic attendance and completion of study assessments (e.g., PROs, health outcomes, etc.), if in the PI's opinion, assistance is needed to comply with all study visits and procedures.

Exclusion Criteria:

1. Any of the warnings, precautions, or contraindications listed in the XADAGO Package Insert that in the opinion of the PI would prevent appropriate treatment with XADAGO or impair study participation (e.g., pregnancy, lactation, severe hepatic impairment, etc.).
2. Participation in any other clinical trial of an investigational drug or device within 4 weeks prior to the Baseline Visit or at any time during the study.
3. Patient is currently receiving chemotherapy or radiation for any form of cancer (if history of cancer, must be in clinical remission at study entry) or currently receiving immunotherapy.
4. Patients with conditions that are likely to prevent them from accurately and reliably completing study assessments, including evidence of moderate or severe dementia as determined by the clinician (not to include mild cognitive impairment [MCI]); major psychiatric illness (specifically diagnosis of schizophrenia, bipolar disorder or a history of attempted suicide); and/or severe and progressive medical illness (including terminal cancer, end-stage renal disease +/- undergoing dialysis).
5. Severe or unpredictable dyskinesia at the time of the Baseline Visit.
6. Previous participation in this study; a patient may not re-enroll after prior discontinuation or completion