Richard Joseph Chadwin, MD
Neurodevelopmental Disabilities Physician · Sonoma, CA
Richard Joseph Chadwin, MD is a neurodevelopmental disabilities physician with a practice address in Sonoma, California, and NPI 1811949399, issued on May 16, 2006. Check the license (California G27274, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Richard Joseph Chadwin
- Credential
- MD
- Primary taxonomy
- Neurodevelopmental Disabilities Physician 2084P0005X
- License number
- G27274 CA
Self-reported in NPPES; status is on the state search - Practice location
- 690 Hudson CT, Sonoma, CA 95476
- Phone
- (707) 849-6533
- Enumerated
- May 16, 2006
- Record last updated
- May 22, 2018 (not updated in 8 years: call before relying on the address or phone)
- Entity
- Type 1 · individual
Verify Richard Joseph Chadwin in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license G27274Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
75% fewer Medicare Part D claims than the average neurodevelopmental disabilities physician in 2024
234 Medicare Part D claims for 11 beneficiaries, against an average of 948 among the 22 providers of this specialty who prescribed in Part D. Brand-name drugs were 11% of claims.
Most prescribed
- Lurasidone Hcl25 claims
- Olanzapine24 claims
- Risperidone20 claims
- Invega Sustenna19 claims
- Benztropine Mesylate15 claims
- Prazosin Hcl14 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Neurodevelopmental Disabilities Physician providers in California
There are 9 neurodevelopmental disabilities physician records in California.
Other neurodevelopmental disabilities physician records in California
- Victoria Dunckley, M.D.Seal Beach, CA1093807000
- Joshua Feder, M.D.Solana Beach, CA1811155161
- Anuja Jindal, MD, MPHSan Diego, CA1194046581
- Aram KimOrange, CA1467814459
- Michael Marcin, M.D., M.S.C.R.Mountain View, CA1528100021
- Lynne Mielke, M.D.Pleasanton, CA1700985413
- Stephen Mott, M.D.Santa Ana, CA1295723450
- Sabira Saifuddin, MDWestlake Village, CA1932233996
Common questions
What is Richard Joseph Chadwin, MD's NPI number?
Richard Joseph Chadwin, MD's National Provider Identifier (NPI) is 1811949399, issued on May 16, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Richard Joseph Chadwin, MD located?
The NPPES record lists a practice address at 690 Hudson CT, Sonoma, CA, 95476. Phone: (707) 849-6533. Providers update this record themselves, so call before visiting.
How can I verify Richard Joseph Chadwin, MD's license?
NPPES lists California license number G27274, as entered by the provider. Search the Medical Board of California at https://www.mbc.ca.gov/License-Verification/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Richard Joseph Chadwin, MD prescribe under Medicare Part D?
In 2024, Richard Joseph Chadwin, MD had 234 Medicare Part D claims for 11 beneficiaries; the average among neurodevelopmental disabilities physician prescribers was 948. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.