Cynthia L. Castillo, M.D.
Internal Medicine Physician · San Antonio, TX
Cynthia L. Castillo, M.D. is an internal medicine physician with a practice address in San Antonio, Texas, and NPI 1457671018, issued on Jun 7, 2010. Check the license (Texas P6150, as entered in NPPES) on the Texas Medical Board; the Medicare figures below come from public CMS files.
- Name
- Cynthia L. Castillo
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- P6150 TX
Self-reported in NPPES; status is on the state search - Practice location
- 4502 Medical Dr, San Antonio, TX 78229
- Phone
- (210) 358-4000
- Enumerated
- Jun 7, 2010
- Record last updated
- Jan 25, 2023
- Medicaid ID
- 323790101 TX
- Medicare enrollment
- Enrolled (PECOS I20130926000310); accepts Medicare assignment
- Medical or professional school
- University Of Texas Medical School At San Antonio, 2010
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 9,175 in Texas → Look up another NPI →
Also registered at 4502 Medical Dr
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Cynthia L. Castillo in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersTexas Medical Board
Search for license P6150Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
27% fewer Medicare Part D claims than the average internal medicine physician in 2024
2,328 Medicare Part D claims for 334 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D.
Most prescribed
- Atorvastatin Calcium148 claims
- Levothyroxine Sodium99 claims
- Lisinopril85 claims
- Rosuvastatin Calcium73 claims
- Montelukast Sodium72 claims
- Metformin Hcl64 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.
Bills Medicare through 2 group practices
- Christus Trinity ClinicSan Antonio, TX
- Rise UP Rehab, LLCSan Antonio, TX
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Cynthia L. Castillo among 9,175 internal medicine physician records in Texas
Cynthia L. Castillo, M.D. is one of 9,175 internal medicine physician records with a practice address in Texas. 82% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2010, is newer than 58% of them.
- NPI issued2010 · 58% of these records are older, 40% newer
- In a Medicare fileYes · 82% of these records are
- In the CMS Doctors and Clinicians fileYes · 66% of these records are
- Graduated2010 · median 2004 among the 6,088 with a school on file
- Record last updated2023 · 49% 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 Texas practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
657 internal medicine physician records list a practice address in San Antonio
They are 657 of the 37,749 NPPES records with a practice address in San Antonio, and 9,175 internal medicine physician records in Texas.
All 9,175 in Texas → Every provider in San Antonio → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Jeremias Abueme, M.D.San Antonio, TX 782291891790960
- Richard Clemons, MDSan Antonio, TX 782291740282664
- Serina Flores, M.D.San Antonio, TX 782291528058203
- John Galan, MDSan Antonio, TX 782291528069440
- Juan Gonzalez, MDSan Antonio, TX 782291659370963
- Bradley Kayser, MDSan Antonio, TX 782291285635110
- Michelle Medellin, M.D.San Antonio, TX 782291770571614
- Thomas Mieras, MDSan Antonio, TX 782291578564787
Common questions
What is Cynthia L. Castillo, M.D.'s NPI number?
Cynthia L. Castillo, M.D.'s National Provider Identifier (NPI) is 1457671018, issued on Jun 7, 2010. An NPI identifies a provider in billing; it is not a license.
Where is Cynthia L. Castillo, M.D. located?
The NPPES record lists a practice address at 4502 Medical Dr, San Antonio, TX, 78229. Phone: (210) 358-4000. Providers update this record themselves, so call before visiting.
How can I verify Cynthia L. Castillo, M.D.'s license?
NPPES lists Texas license number P6150, as entered by the provider. Search the Texas Medical Board at https://profile.tmb.state.tx.us/Search.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Cynthia L. Castillo, M.D. prescribe under Medicare Part D?
In 2024, Cynthia L. Castillo, M.D. had 2,328 Medicare Part D claims for 334 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.
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.