NPI registry status
Active
2026 NPPES data Internal Medicine Physician NPI 1952680282 MD
Verify on CMS → Hernan Zamalloa Castro, MD
Internal Medicine Physician in Corpus Christi, Texas.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 174,792 in Internal Medicine Physician, and covers specialty classification, practice address, and Medicare Part D prescribing data when reported. According to CMS, every field reflects the provider's official federal registration, see our methodology.
Federal data, no proprietary rating.
We show these CMS records as-is - no composite score, no star rating, no editorial opinion layered on top.
Prescribing volume
346
Medicare Part D claims · 179 beneficiaries · Internal Medicine Physician avg: 3K
What the federal data shows
Hernan Zamalloa Castro, MD filed 346 Medicare Part D claims in 2024 as an Internal Medicine Physician in Corpus Christi, Texas.
- 346
- Part D claims, 2024
- Likely
- board-certified (heuristic)
- ≥56th
- pct by Part D claim volume (lower-bound band)
Every figure on this page comes straight from federal CMS records (NPPES, Medicare Part D, MIPS, Open Payments) - no proprietary rating or editorial opinion is applied.
Federal trust snapshot
What official records show about Hernan Zamalloa Castro, MD
Federal records show an active NPI with Medicare Part D prescribing activity — verifiable registry data, not a proprietary rating.
- Verified
NPI registry status
Active listing in the CMS National Provider Identifier Registry (NPI 1952680282), first enumerated 08/04/2011.
Source: CMS NPPES
- Reported
Medicare Part D participation
Filed 346 Medicare Part D prescription claims in the 2023 CMS public use file — indicates active Medicare prescribing participation.
Source: CMS Part D Prescriber PUF
- Reported
Board certification signal
Heuristic suggests board-certified status based on ABMS-eligible specialty taxonomy plus active CMS participation signals — not a direct ABMS verification.
- Reported
Hospital affiliations
1 CMS Care Compare hospital affiliation on record — practice footprint from the Doctors and Clinicians file.
Source: CMS Care Compare
- State context
State board disciplinary context
Texas statewide board action statistics are published annually — these figures describe aggregate state activity, not Hernan Zamalloa Castro, MD's individual license status. Verify directly with the state medical board.
Source: TMB annual report 2023
- Not in federal data
Individual sanction lookup
PlainDoctor does not publish per-provider disciplinary determinations. Confirm current license and any individual actions through the state medical board or FSMB verification service.
Source: State medical board / FSMB
This trust snapshot summarizes only what appears in federal CMS/NPPES public records. It is not a composite score, star rating, patient review, or clinical recommendation. PlainDoctor never fabricates reviews or AggregateRating schema.
CMS NPPES provider registry desk
NPI 1952680282 · Internal Medicine Physician
NPI-10 · ENUM-MID · TAX-MEGA · RX-LIGHT · BOOK-MID · PHOTO-ENUM
- NPI-10 1952680282
- ENUM-MID 2011
- TAX-MEGA 175K Internal Medicine
- RX-LIGHT 346
- BOOK-MID 11,069 in Texas
- PHOTO-ENUM Jonathan Daniels · 2011
Hernan Zamalloa Castro, MD's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2024, across all CMS prescribers nationally
346 ≥ 56th percentile 56% of 1,416,883 prescribers are in lower value bands
Each bar is a band; taller bars hold more prescribers. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
The percentile is a conservative 100-claim band: it counts only prescribers in lower claim-volume bands. Medicare Part D claim volume is activity context, not a quality measure or recommendation. See methodology § corpus placement.
Source CMS Medicare Part D Prescriber Public Use File · 2024
✓
Board certification likely (heuristic, not verified)
Hernan Zamalloa Castro, MD practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 1 hospital affiliation - signals consistent with board-certified status. For verified board certification, see CertificationMatters.org (the official ABMS public lookup).
What does the federal data show about Hernan Zamalloa Castro, MD?
Quality data not reportedPrimary specialty
Internal Medicine Physician
Medicare Part D claims
346 88% vs specialty avg
Specialty distribution in Texas
How Internal Medicine Physician compares to other specialties among Texas providers
Board certification
Not published by CMS
CMS does not publish a per-provider board-certification field in NPPES. PlainDoctor does not have a reliable per-specialty certification rate to show for Internal Medicine Physician. Verify directly:
How MIPS and board certification work
The Merit-based Incentive Payment System (MIPS) scores providers 0–100 across four performance categories: Quality, Cost, Promoting Interoperability, and Improvement Activities, weighted under 42 CFR §414.1380. Reporting is voluntary for many small practices, so absence of a MIPS score is not a quality signal.
Board certification through an ABMS or AOA member board signals voluntary post-licensure examination plus continuous Maintenance of Certification cycles. Verify any individual provider's status through certificationmatters.org (ABMS) or osteopathic.org (AOA).
Practice Address
Provider Details
| NPI | 1952680282 |
|---|---|
| Specialty | Internal Medicine Physician |
| Credentials | MD |
| Gender | Male |
| NPI Issued | 08/04/2011 |
Hospital and facility affiliations
Facilities where Hernan Zamalloa Castro, MD bills Medicare from. Star ratings (1-5) are CMS Hospital Compare's "Hospital overall rating" - a composite of mortality, readmission, patient experience, safety, timely care, and efficient use of medical imaging measures. Source: CMS Care Compare.
Hha Hospital Medicine OF Texas PLLC
Huntsville, TX
Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).
License & disciplinary context - Texas TMB 2023 annual report
Aggregate state board data only, NOT a determination of any individual provider's status. The figures below describe statewide disciplinary activity across all ~77K Texas medical licensees in 2023 - they are NOT specific to Hernan Zamalloa Castro, MD. To verify Hernan Zamalloa Castro, MD's current license status, search the TMB public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.
344
Total board actions, Texas 2023
Across 334 cases
4.47
Actions per 1,000 licensees
Texas statewide rate
probation
Most common action type
94 cases
TMB publishes annual disciplinary statistics as part of public-record reporting under each state's Administrative Procedure Act. See the full breakdown by action type and year on the Texas disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.
Medicare Part D Prescribing Data
CMS Medicare Part D prescriber-level data for calendar year 2024.
346
Total Claims
$12K
Total Drug Cost
179
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 372.967
- Total Day Supply
- 7,177
- Generic Drug Cost
- $2K
- Opioid Claims
- 29 (8.4% rate)
- Antibiotic Claims
- 107
Patient Demographics
- Average Patient Age
- 72.6 years
- Avg HCC Risk Score
- 2.64
- Gender Split
- 49% female / 51% male
- Age Distribution
- <65: 26, 65-74: 76, 75-84: 56, 85+: 21
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2024. Based on Medicare Part D data only.
What Hernan Zamalloa Castro, MD prescribes most
Top Medicare Part D drugs by claim count, 2024
- Amoxicillin-Clavul…
Amoxicillin-Clavulanate Potass
30 claims
- Amlodipine Besylate
Amlodipine Besylate
21 claims
- Tramadol Hcl
Tramadol Hcl
21 claims
- Cefuroxime
Cefuroxime
19 claims
- Doxycycline Monohy…
Doxycycline Monohydrate
13 claims
- Furosemide
Furosemide
13 claims
- Clopidogrel
Clopidogrel
12 claims
- Doxycycline Hyclate
Doxycycline Hyclate
12 claims
| Drug | Claims |
|---|---|
| Amoxicillin-Clavulanate Potass Amoxicillin/Potassium Clav | 30 |
| Amlodipine Besylate | 21 |
| Tramadol Hcl | 21 |
| Cefuroxime Cefuroxime Axetil | 19 |
| Doxycycline Monohydrate | 13 |
| Furosemide | 13 |
| Clopidogrel Clopidogrel Bisulfate | 12 |
| Doxycycline Hyclate | 12 |
| Eliquis Apixaban | 12 |
| Metoprolol Succinate | 12 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Internal Medicine Physician Overview
How Hernan Zamalloa Castro, MD fits within the Internal Medicine Physician landscape nationally.
174,792
Internal Medicine Physician Providers in US
56
States with Internal Medicine Physician
2,785
Avg Claims per Provider
Hernan Zamalloa Castro, MD's 346 claims are below the specialty average of 2,785.
Nationwide Internal Medicine Physician peers with similar MIPS or enrollment year
Two federal-record peer sets for Zamalloa Castro, both outside Texas so the neighborhoods are not geographic containment.
Same NPPES enumeration year (2011)
Same-specialty clinicians who entered the NPI registry in the same calendar year, outside this state.
Nearby Internal Medicine Physician Providers in Texas
Other clinicians with the same primary specialty enrolled in Texas, drawn from the same CMS NPPES roster as Zamalloa Castro.
One of 11,069 Internal Medicine Physician providers enrolled in Texas, 5 are shown here.
Dr. Muhammad A. Sattar
MD
Dallas, TX
Dr. Gayatri Aaluri
MD
Galveston, TX
Anunaya Aashish
Denton, TX
Dr. Queenie Ann Abad
M.D.
San Antonio, TX
Dr. Fuad Abaleka
M.D
Lubbock, TX
Compare Internal Medicine Physician nationally: see state-by-state distribution →
Frequently Asked Questions
What is Hernan Zamalloa Castro, MD's specialty? ▼
Hernan Zamalloa Castro, MD specializes in Internal Medicine Physician and practices in Corpus Christi, Texas. Credentials: MD.
How much does Hernan Zamalloa Castro, MD prescribe under Medicare Part D? ▼
In 2024, Hernan Zamalloa Castro, MD wrote 346 Medicare Part D claims totaling $12K in drug costs for 179 beneficiaries.
Where is Hernan Zamalloa Castro, MD located? ▼
Hernan Zamalloa Castro, MD is located at 3315 S ALAMEDA ST, Corpus Christi, TX, 78411. Phone: (361) 882-3198.
What is Hernan Zamalloa Castro, MD's NPI number? ▼
Hernan Zamalloa Castro, MD's National Provider Identifier (NPI) is 1952680282, issued on 08/04/2011.
Does Hernan Zamalloa Castro, MD prescribe opioids? ▼
Yes, Hernan Zamalloa Castro, MD had 29 opioid claims in 2024 with an opioid prescribing rate of 8.4%.
How many Internal Medicine Physician providers are there in the US? ▼
There are 174,792 Internal Medicine Physician providers across 56 states in the US. The average Internal Medicine Physician provider writes 2,785 Medicare Part D claims per year.
What drugs does Hernan Zamalloa Castro, MD prescribe most often? ▼
Based on 2024 Medicare Part D data, Hernan Zamalloa Castro, MD's most frequently prescribed drugs include Amoxicillin-Clavulanate Potass, Amlodipine Besylate, Tramadol Hcl. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Hernan Zamalloa Castro, MD accept Medicare? ▼
Hernan Zamalloa Castro, MD appears in CMS Medicare data with 346 Part D claims and 179 Medicare beneficiaries in 2024. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Hernan Zamalloa Castro, MD's credentials? ▼
Hernan Zamalloa Castro, MD's NPI is 1952680282 with credentials MD. You can verify this through the NPPES NPI Registry, check state medical board records, and confirm board certification through the ABMS or AOA.
Data Sources
View source datasets and methodology notes
- Provider Directory
- CMS National Plan and Provider Enumeration System (NPPES), download.cms.gov/nppes, updated monthly. Contains NPI, specialty, credentials, and practice location.
- Specialty Classification
- NUCC Health Care Provider Taxonomy (nucc.org), the industry standard for classifying provider specialties in Medicare and Medicaid billing.
- Prescribing Data
- CMS Medicare Part D Prescriber Public Use File (2024). Includes claims, drug costs, beneficiaries, and opioid prescribing rates.
- Limitations
- Provider data is self-reported to CMS. Prescribing data reflects Medicare Part D only and does not include commercial insurance, Medicaid, or cash prescriptions. Claims below 11 beneficiaries are suppressed by CMS for privacy.
See our complete data methodology for details on how we collect and process government data.
Data as of August 2026 (NPPES) / 2024 (Medicare Part D). Source: Centers for Medicare & Medicaid Services (CMS).
Disclaimer: Data from CMS NPPES and Medicare Part D. PlainDoctor does not rate or rank providers. Provider information is self-reported and may not be current. Always verify information directly with the provider. About · Methodology
Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of August 2026.