2026 NPPES data Internal Medicine Physician NPI 1083792352 MD
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JOSE MARCIANO CASTRO, MD

Internal Medicine Physician in WILMINGTON, Delaware. CMS National Plan and Provider Enumeration System profile including specialty classification, practice address, and Medicare prescribing data when reported.

Federal data — no proprietary rating. PlainDoctor publishes the actual CMS NPPES and Medicare records — NPI registration, specialty, practice location, and prescribing data — without a composite score or editorial opinion on top. Every field traces to a federal source.
Prescribing volume
12K
Medicare Part D claims · 693 beneficiaries · Internal Medicine Physician avg: 3K
Generic prescribing
82%
generic claims · 18% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$3.5K
158 payments · CMS Open Payments (Sunshine Act)

What the federal data shows

JOSE MARCIANO CASTRO, MD filed 12,316 Medicare Part D claims in 2023 as a Internal Medicine Physician in WILMINGTON, Delaware, prescribing 82% generic.

12K
Part D claims, 2023
82%
generic prescribing
Likely
board-certified (heuristic)

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.

JOSE MARCIANO CASTRO, MD's Medicare Part D volume vs every U.S. prescriber

Total Medicare Part D claims, 2023 — across all CMS prescribers nationally

12,316 Top 2% higher than 98% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). Below this entry. 200–400: 182,923 prescribers (13%). Below this entry. 400–600: 90,619 prescribers (7%). Below this entry. 600–800: 56,224 prescribers (4%). Below this entry. 800–1,000: 40,919 prescribers (3%). Below this entry. 1,000–1,200: 31,827 prescribers (2%). Below this entry. 1,200–1,400: 26,224 prescribers (2%). Below this entry. 1,400–1,600: 21,710 prescribers (2%). Below this entry. 1,600–1,800: 19,072 prescribers (1%). Below this entry. 1,800–2,000: 16,451 prescribers (1%). Below this entry. 2,000–2,200: 213,991 prescribers (16%). This entry sits in this band. This provider 0 2K+ every Part D prescriber (claims/yr), bucketed by value

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.

Source CMS Medicare Part D Prescriber Public Use File · 2023

Board certification likely (heuristic — not verified)

JOSE MARCIANO 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 JOSE MARCIANO CASTRO, MD?

Quality data not reported

NPI registry status

Active

Issued 11/02/2006

NPI 1083792352

Primary specialty

Internal Medicine Physician

High-volume

172,858 US NPIs in this specialty

Medicare Part D claims

12,316 353% vs specialty avg

2023 prescription claims

Specialty avg: 2,716

Specialty distribution in Delaware

How Internal Medicine Physician compares to other specialties among Delaware providers

Delaware providers

Internal Medicine Physician share within Delaware

1. Internal Medicine Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Internal Medicine Physician share within Delaware

Specialty board-certification context

Estimated specialty board-certified rate — Internal Medicine Physician (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Internal Medicine Physician ABMS/AOA estimate

Est. board-certified rate (Internal Medicine Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Internal Medicine Physician) — ABMS / AOA estimate

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).

JOSE MARCIANO CASTRO, MD appears in the CMS NPPES registry as a Internal Medicine Physician provider holding MD credentials at 2055 LIMESTONE RD, WILMINGTON, DE, 19808, with a listed phone of (302) 999-8169. NPI 1083792352 was issued on 11/02/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what CASTRO most recently submitted to CMS rather than a vetted directory listing, which is why patients should always confirm the practice is still at this location before scheduling.

Medicare Part D records for calendar year 2023 show 12,316 prescription claims written by this provider, covering 693 Medicare beneficiaries and totaling roughly $2.3 million in drug spend, split 18% brand-name and 82% generic by claim count, with an opioid prescribing rate of 2.5%. These figures capture only Medicare Part D — commercial insurance, Medicaid, and cash-pay prescriptions are not included, and any drug-beneficiary cell under 11 is suppressed by CMS for patient privacy.

Internal Medicine Physician is a high-volume specialty nationwide, with 172,858 enrolled providers across 56 states and an average of 2,716 Part D claims per prescriber, so the context for interpreting these metrics differs meaningfully from a primary-care baseline. Important: PlainDoctor is a directory of publicly available government data, not medical advice, a malpractice database, or a quality rating. Inclusion here does not imply a recommendation, and absence of complaints or sanctions on this page does not mean none exist — always verify credentials through the NPPES NPI Registry, your state medical board, and the ABMS or AOA before making healthcare decisions.

Practice Address

2055 LIMESTONE RD
WILMINGTON, DE 19808

Provider Details

NPI 1083792352
Specialty Internal Medicine Physician
Credentials MD
Gender Male
NPI Issued 11/02/2006

Hospital and facility affiliations

Facilities where JOSE MARCIANO 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.

FIRST STATE MEDICAL ASSOCIATES
WILMINGTON, DE

Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).

Industry payments received (2024) — CMS Open Payments transparency data

The federal Physician Payments Sunshine Act (part of the Affordable Care Act) requires drug and medical-device manufacturers + group purchasing organizations to publicly report payments and other transfers of value to physicians and teaching hospitals. The data below covers 2024 for JOSE MARCIANO CASTRO, MD. Source: openpaymentsdata.cms.gov.

Total received

$3.5K

Largest payer

AstraZeneca Pharmaceuticals LP

Most common payment type

Food and Beverage

Industry payments are not necessarily indicators of bias — they include research funding, consulting fees for evidence-based work, royalties for inventions, food at conferences, and similar items. The disclosure exists for transparency. Read our methodology for how we interpret this data.

Brand vs generic prescribing mix · Typical

JOSE MARCIANO CASTRO, MD — brand share 18.0%
Specialty average (est.)

18% brand-name claims vs 82% generic, on 12,316 2023 Medicare Part D claims.

The federal Medicare Part D Generic Dispensing Rate national benchmark sits near 90% generic / 10% brand for primary-care prescribers, per CMS Office of the Actuary 2024 estimates. Higher brand share is common in specialty prescribing where generic equivalents are not available.

Medicare Part D Prescribing Data

CMS Medicare Part D prescriber-level data for calendar year 2023.

12,316
Total Claims
$2.3M
Total Drug Cost
693
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
25,361
Total Day Supply
740,989
Brand vs Generic
18% brand / 82% generic
Brand Drug Cost
$2.0M
Generic Drug Cost
$261K
Opioid Claims
312 (2.5% rate)
Antibiotic Claims
207

Patient Demographics

Average Patient Age
69.2 years
Avg HCC Risk Score
1.49
Gender Split
49% female / 51% male
Age Distribution
<65: 169, 65-74: 316, 75-84: 165, 85+: 43

Top Prescribed Drugs (Medicare Part D)

Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.

What JOSE MARCIANO CASTRO, MD prescribes most

Top Medicare Part D drugs by claim count, 2023

claims
Source CMS Medicare Part D Prescriber Public Use File As of 2023
Drug Claims
Atorvastatin Calcium
737
Amlodipine Besylate
513
Omeprazole
440
Gabapentin
423
Rosuvastatin Calcium
412
Metformin Hcl
392
Olmesartan-Hydrochlorothiazide
Olmesartan/Hydrochlorothiazide
253
Levothyroxine Sodium
241
Carvedilol
217
Metoprolol Succinate
208

* 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 JOSE MARCIANO CASTRO, MD fits within the Internal Medicine Physician landscape nationally.

172,858
Internal Medicine Physician Providers in US
56
States with Internal Medicine Physician
2,716
Avg Claims per Provider

JOSE MARCIANO CASTRO, MD's 12,316 claims are above the specialty average of 2,716.

Nearby Internal Medicine Physician Providers in Delaware

Other clinicians with the same primary specialty enrolled in Delaware, drawn from the same CMS NPPES roster as CASTRO.

Compare Internal Medicine Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is JOSE MARCIANO CASTRO, MD's specialty?
JOSE MARCIANO CASTRO, MD specializes in Internal Medicine Physician and practices in WILMINGTON, Delaware. Credentials: MD.
How much does JOSE MARCIANO CASTRO, MD prescribe under Medicare Part D?
In 2023, JOSE MARCIANO CASTRO, MD wrote 12,316 Medicare Part D claims totaling $2.3M in drug costs for 693 beneficiaries.
Where is JOSE MARCIANO CASTRO, MD located?
JOSE MARCIANO CASTRO, MD is located at 2055 LIMESTONE RD, WILMINGTON, DE, 19808. Phone: (302) 999-8169.
What is JOSE MARCIANO CASTRO, MD's NPI number?
JOSE MARCIANO CASTRO, MD's National Provider Identifier (NPI) is 1083792352, issued on 11/02/2006.
Does JOSE MARCIANO CASTRO, MD prescribe more brand-name or generic drugs?
JOSE MARCIANO CASTRO, MD's prescribing is 18% brand-name and 82% generic drugs by claim count, with $2.0M in brand drug costs.
Does JOSE MARCIANO CASTRO, MD prescribe opioids?
Yes, JOSE MARCIANO CASTRO, MD had 312 opioid claims in 2023 with an opioid prescribing rate of 2.5%.
How many Internal Medicine Physician providers are there in the US?
There are 172,858 Internal Medicine Physician providers across 56 states in the US. The average Internal Medicine Physician provider writes 2,716 Medicare Part D claims per year.
What drugs does JOSE MARCIANO CASTRO, MD prescribe most often?
Based on 2023 Medicare Part D data, JOSE MARCIANO CASTRO, MD's most frequently prescribed drugs include Atorvastatin Calcium, Amlodipine Besylate, Omeprazole. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does JOSE MARCIANO CASTRO, MD accept Medicare?
JOSE MARCIANO CASTRO, MD appears in CMS Medicare data with 12,316 Part D claims and 693 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify JOSE MARCIANO CASTRO, MD's credentials?
JOSE MARCIANO CASTRO, MD's NPI is 1083792352 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

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 (2023). 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 April 2026 (NPPES) / 2023 (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