Errol Olwyn Grannum, MD
NPI 1508897935ActiveIndividual· Ophthalmology· McAllen, TX
Ophthalmology (MD) in McAllen, Texas, trained at Yale University School of Medicine (class of 1989). Their prescriptions cost Medicare Part D more than their services did: $1,048,379 for 9,495 claims, against $79,245 paid for services in 2024. Abbvie Inc. was the largest of 5 companies reporting payments in 2025, $317.98 in all, mostly food and beverage.
Overview
| NPI | 1508897935 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | MD |
| Sole proprietor | Yes |
| NPI issued | Jul 5, 2006 |
| Last updated in NPPES | Jul 8, 2007 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Ophthalmology Primary | 207W00000X | K5972 | TX |
Exclusion screening
| List | Result | Details |
|---|---|---|
| HHS-OIG LEIE · Nov 10, 2026 | No match | Checked by NPI and by name + state |
| North Carolina Medicaid · Nov 11, 2026 | No match | — |
| New York OMIG · Nov 11, 2026 | No match | — |
| Ohio Medicaid · Nov 11, 2026 | No match | — |
| Pennsylvania Medicheck · Nov 11, 2026 | No match | — |
| Washington HCA · Nov 11, 2026 | No match | — |
Official OIG search · How matching works ·Bulk check a roster
Medicare
| Enrollment (PECOS) | Enrolled Practitioner - Ophthalmology (TX) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 325 |
|---|---|
| Services billed | 2,116 across 27 procedure codes |
| Paid by Medicare | $79,245 |
Part D prescriptions in 2024
| Prescriptions (claims) | 9,495 · 14,068 30-day fills |
|---|---|
| Patients | 1,076 |
| Total drug cost | $1,048,379 |
| Generic share | 65% of claims |
Education and affiliations
| Medical school | Yale University School of Medicine |
|---|---|
| Graduation year | 1989 |
| Medicare specialty | Ophthalmology |
Hospital affiliation
- Rio Grande Regional HospitalMcAllen, TX
Industry payments (Open Payments)
- 2025$317.98 · 22 payments from 5 companies
- 2024$497.92 · 24 payments from 6 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Abbvie Inc. | $150.32 | 12 |
| Alcon Vision LLC | $74.92 | 5 |
| Amgen Inc. | $37.75 | 2 |
| Bausch & Lomb Americas Inc. | $33.41 | 2 |
| Thea Pharma Inc. | $21.58 | 1 |
What the 2025 payments were for
- Food and Beverage$317.98 · 22 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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All 27 ophthalmologists in McAllen · All ophthalmologists in Texas