NPPES file of Aug 9, 2026

Robert M. Castro, DO

Internal Medicine Physician · Santa Ana, CA

Robert M. Castro, DO is an internal medicine physician with a practice address in Santa Ana, California, and NPI 1285777813, issued on Feb 14, 2007. Check the license (California 20A9770, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.

Record from CMS NPPES, file of Aug 9, 2026 · Medicare files 2024 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1285777813
Name
Robert M. Castro
Credential
DO
Primary taxonomy
Internal Medicine Physician 207R00000X
License number
20A9770 CA
Self-reported in NPPES; status is on the state search
Practice location
2621 S Bristol St, Santa Ana, CA 92704
Phone
(714) 754-1684
Enumerated
Feb 14, 2007
Record last updated
May 27, 2015 (not updated in 11 years: call before relying on the address or phone)
Fax
(714) 966-0417
Medicaid ID
00AX97700 CA
Medicare enrollment
Enrolled (PECOS I20070523000750); accepts Medicare assignment
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). Enrollment, assignment, school and telehealth: CMS Doctors and Clinicians file, Aug 2026. A record is not a license: verify it with the state board.
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8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →

Also registered at 2621 S Bristol St

A shared address usually means a shared clinic or building; it does not show who employs whom.

  1. Rose Cunningham-Ahumada, D.O.Ophthalmology Physician1811996523
  2. Ma Angelica CuyuganFamily Nurse Practitioner1386195105
  3. Paul Han, DPMFoot & Ankle Surgery Podiatrist1972506988
  4. Alan Schwartz, MDInternal Medicine Physician1023183480
  5. Anil Shah, M.D.Specialist1619997368
  6. Stacey Shoop, M.D.Medical Physician Assistant1104222124

Verify Robert M. Castro in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license 20A9770    Check the board
  3. 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
  4. 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
  5. 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Open the California license search

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22% fewer Medicare Part D claims than the average internal medicine physician in 2024

2,481 Medicare Part D claims for 361 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 21% of claims.

  1. Robert Castro2,481
  2. Specialty average3,176

Most prescribed

  1. Eliquis278 claims
  2. Metoprolol Succinate188 claims
  3. Carvedilol172 claims
  4. Metoprolol Tartrate162 claims
  5. Amlodipine Besylate157 claims
  6. Nifedipine Er154 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: $1,464.79

58 payments; by number, the most common kind was food and beverage; the largest payer was Boston Scientific Corporation. The 50,334 providers of this specialty with any payment received $1,303.06 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.

  1. Robert Castro$1,464.79
  2. Specialty average$1,303.06

Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.

Robert M. Castro among 17,696 internal medicine physician records in California

Robert M. Castro, DO is one of 17,696 internal medicine physician records with a practice address in California. 79% 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 44% of them.

  • NPI issued2007 · 44% of these records are older, 44% newer
  • In a Medicare fileYes · 79% of these records are
  • In the CMS Doctors and Clinicians fileYes · 63% of these records are
  • Graduated2005 · median 2004 among the 11,065 with a school on file
  • Record last updated2015 · 61% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207R00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

Internal Medicine Physician providers in California

There are 17,696 internal medicine physician records in California.

All 17,696 in California → Every provider in Santa Ana → Internal Medicine Physician nationwide →

The 8 internal medicine physician records with the nearest ZIP codes

  1. Ronnie Alas, M.D.Santa Ana, CA 927041306267026
  2. Robin Hatam, D.O.Santa Ana, CA 927041194053785
  3. Iyad Houshan, M.D.Santa Ana, CA 927041497773287
  4. Wesam Houshan, MDSanta Ana, CA 927041356467112
  5. Ajay Meka, M.D.Santa Ana, CA 927041063527976
  6. Meena Meka, M.D.Santa Ana, CA 927041013338722
  7. Madhavi Mulye, M.D.Santa Ana, CA 927041205056470
  8. Hima Natla, M.D.Santa Ana, CA 927041730366139

Common questions

What is Robert M. Castro, DO's NPI number?

Robert M. Castro, DO's National Provider Identifier (NPI) is 1285777813, issued on Feb 14, 2007. An NPI identifies a provider in billing; it is not a license.

Where is Robert M. Castro, DO located?

The NPPES record lists a practice address at 2621 S Bristol St, Santa Ana, CA, 92704. Phone: (714) 754-1684. Providers update this record themselves, so call before visiting.

How can I verify Robert M. Castro, DO's license?

NPPES lists California license number 20A9770, 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 Robert M. Castro, DO prescribe under Medicare Part D?

In 2024, Robert M. Castro, DO had 2,481 Medicare Part D claims for 361 beneficiaries; the average among internal medicine physician prescribers was 3,176. 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.

Written with AI tools from the named public files; every figure is computed from those files (how it is made).

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.