Richard Chadwin, MD
NPI 1811949399 · Neurodevelopmental Disabilities Physician · Sonoma, CA
Richard Chadwin, MD is a Neurodevelopmental Disabilities Physician provider in Sonoma, CA (NPI 1811949399).
Provider details
- NPI number
- 1811949399
- Entity type
- Individual
- Primary specialty
- Neurodevelopmental Disabilities PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- G27274 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
20 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
1 documented practice location
Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 8 distinct drugs on file.
| Drug | Part D claims (2024) |
|---|---|
| Lurasidone Hcl | 25 |
| Olanzapine | 24 |
| Risperidone | 20 |
| Paliperidone Palmitatebrand: Invega Sustenna | 19 |
| Benztropine Mesylate | 15 |
| Prazosin Hcl | 14 |
| Divalproex Sodium | 13 |
| Sertraline Hcl | 12 |
Medicare Part D only. These counts cover prescriptions paid through Medicare Part D in 2024 — they do notinclude cash-pay, commercial-insurance, Medicaid, or Part B–administered drugs, and badly undercount high cash-pay categories (e.g. GLP-1 weight-loss, testosterone, and ED medications). Any drug with 10 or fewer claims is omitted by CMS, and beneficiary counts under 11 are suppressed — so a missing drug means no Part D record, never zero. This is a factual claims summary, not an endorsement, not medical advice, and not a consumer report. Source: CMS Medicare Part D Prescribers — by Provider and Drug.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-05-16
- Last updated
- 2018-05-22
Frequently asked questions
- What is Richard Chadwin's NPI number?
- Richard Chadwin's National Provider Identifier (NPI) is 1811949399, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Richard Chadwin's specialty?
- Richard Chadwin is listed in the NPPES registry with a primary specialty of Neurodevelopmental Disabilities Physician (Allopathic & Osteopathic Physicians).
- Where is Richard Chadwin located?
- Richard Chadwin's practice location on file with NPPES is 690 Hudson Ct, Sonoma, CA 95476.
- What is Richard Chadwin's phone number?
- The practice phone number listed in the NPPES registry for Richard Chadwin is (707) 849-6533.
- Is Richard Chadwin's NPI active?
- Yes — Richard Chadwin's NPI (1811949399) is active in the NPPES registry as of the last update on 2018-05-22.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.