William Thomas Riley, M.D.
Psychiatry Physician · Palo Alto, CA
William Thomas Riley, M.D. is a psychiatry physician with a practice address in Palo Alto, California, and NPI 1639384118, issued on May 10, 2007. Check the license (California G22128, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- William Thomas Riley
- Credential
- M.D.
- Primary taxonomy
- Psychiatry Physician 2084P0800X
- License number
- G22128 CA
Self-reported in NPPES; status is on the state search - Practice location
- 451 Chaucer St, Palo Alto, CA 94301
- Phone
- (650) 740-2083
- Enumerated
- May 10, 2007
- Record last updated
- Jul 8, 2007 (not updated in 19 years: call before relying on the address or phone)
- Fax
- (650) 289-9500
- Entity
- Type 1 · individual
8 nearest psychiatry physician records → All 8,673 in California → Look up another NPI →
Verify William Thomas Riley in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license G22128Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
95% fewer Medicare Part D claims than the average psychiatry physician in 2024
49 Medicare Part D claims, against an average of 1,000 among the 35,054 providers of this specialty who prescribed in Part D. Brand-name drugs were 0% of claims.
Most prescribed
- Lorazepam25 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.
Industry payments in 2024: $21.93
1 payment: food and beverage; the largest payer was Davol Inc. The 13,693 providers of this specialty with any payment received $4,954.93 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
William Thomas Riley among 8,673 psychiatry physician records in California
William Thomas Riley, M.D. is one of 8,673 psychiatry physician records with a practice address in California. 67% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2007, is newer than 33% of them.
- NPI issued2007 · 33% of these records are older, 48% newer
- In a Medicare fileYes · 67% of these records are
- In the CMS Doctors and Clinicians fileNo · 38% of these records are
- Record last updated2007 · 54% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 2084P0800X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
215 psychiatry physician records list a practice address in Palo Alto
They are 215 of the 7,617 NPPES records with a practice address in Palo Alto, and 8,673 psychiatry physician records in California.
All 8,673 in California → Every provider in Palo Alto → Psychiatry Physician nationwide →
The 8 psychiatry physician records with the nearest ZIP codes
- Ulka Agarwal, MDPalo Alto, CA 943011689684151
- Richard Corelli, M.D.Palo Alto, CA 943011912995507
- Katherine Devaul, M.D.Palo Alto, CA 943011659383636
- Perrin French, MDPalo Alto, CA 943011780762369
- Shirin Hoodei, M.D.Palo Alto, CA 943011184714610
- Gale Hylton, MDPalo Alto, CA 943011043321367
- Gloria Kardong, MDPale Alto, CA 943011386707131
- Nan Link, MDPalo Alto, CA 943011720199052
Common questions
What is William Thomas Riley, M.D.'s NPI number?
William Thomas Riley, M.D.'s National Provider Identifier (NPI) is 1639384118, issued on May 10, 2007. An NPI identifies a provider in billing; it is not a license.
Where is William Thomas Riley, M.D. located?
The NPPES record lists a practice address at 451 Chaucer St, Palo Alto, CA, 94301. Phone: (650) 740-2083. Providers update this record themselves, so call before visiting.
How can I verify William Thomas Riley, M.D.'s license?
NPPES lists California license number G22128, 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 William Thomas Riley, M.D. prescribe under Medicare Part D?
In 2024, William Thomas Riley, M.D. had 49 Medicare Part D claims; the average among psychiatry physician prescribers was 1,000. 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.