Margarita C. Castro-Zarraga, M.D.
NPI 1578705679ActiveIndividual· Family Medicine· Lowell, MA
Family Medicine (M.D.) with Concord Medical Group of Texas PLLC and 3 other groups, practicing in Lowell, Massachusetts. Their prescriptions cost Medicare Part D more than their services did: $539,373 for 4,127 claims, against $960.19 paid for services in 2024. Corcept Therapeutics reported $63.25 in payments in 2025, mostly food and beverage. Lists Clay County Memorial Hospital and 4 other hospitals as hospital affiliations.
Overview
| NPI | 1578705679 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M.D. |
| Sole proprietor | No |
| NPI issued | Apr 3, 2009 |
| Last updated in NPPES | Jan 3, 2024 |
| Certified by provider | Jan 3, 2024 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Family Medicine Primary | 207Q00000X | 251722 | MA |
Exclusion screening
| List | Result | Details |
|---|---|---|
| HHS-OIG LEIE · Oct 9, 2026 | No match | Checked by NPI and by name + state |
| North Carolina Medicaid · Nov 10, 2026 | No match | — |
| New York OMIG · Nov 10, 2026 | No match | — |
| Ohio Medicaid · Nov 10, 2026 | No match | — |
| Pennsylvania Medicheck · Nov 10, 2026 | No match | — |
| Washington HCA · Nov 10, 2026 | No match | — |
Official OIG search · How matching works ·Bulk check a roster
Medicare
| Enrollment (PECOS) | Enrolled Practitioner - Family Practice (MA); Practitioner - Family Practice (TX) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 31 |
|---|---|
| Services billed | 46 across 10 procedure codes |
| Paid by Medicare | $960.19 |
Part D prescriptions in 2024
| Prescriptions (claims) | 4,127 · 7,721 30-day fills |
|---|---|
| Patients | 300 |
| Total drug cost | $539,373 |
| Generic share | 78% of claims |
Education and affiliations
| Graduation year | 2005 |
|---|---|
| Medicare specialty | Family Practice |
Medical groups
- Concord Medical Group of Texas PLLCBreckenridge, TX · 321 clinicians
- Concord Medical Group PLLCTulia, TX · 180 clinicians
- Em Alliance Texas PLLCAmarillo, TX · 82 clinicians
- Hospitalist Medicine Physicians of Texas - Houston, PLLCPlainview, TX · 18 clinicians
Hospital affiliations
- Clay County Memorial HospitalHenrietta, TX
- Comanche County Medical CenterComanche, TX
- Covenant Hospital PlainviewPlainview, TX
- Northwest Texas HospitalAmarillo, TX
- United Regional Health Care SystemWichita Falls, TX
Other facilities
- Healing Hands Healthcare LLCHome health agency · Wichita Falls, TX
- Briarwood Rehabilitation & Healthcare CenterNursing home · Needham, MA
Industry payments (Open Payments)
- 2025$63.25 · 3 payments from 1 company
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Corcept Therapeutics | $63.25 | 3 |
What the 2025 payments were for
- Food and Beverage$63.25 · 3 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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