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ERROL O GRANNUM
NPI 1457377194
Ophthalmology in Mcallen, TX

Active since July 14, 2006
1910 S 1ST ST, SUITE 400, MCALLEN, TX 78503(956) 687-3937(956) 687-3938 Get Directions Write a Review

NPPES record last updated: August 22, 2020. Verified against the NPPES registry weekly; last sync: October 18, 2026.

About Errol O Grannum NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

ERROL O GRANNUM (NPI 1457377194) is a healthcare organization registered as an ophthalmology in Mcallen, Texas and active in the NPI registry since July 2006. The organization lists Errol Olwyn Grannum, Owner, as its authorized official.

NPPES Registry Identity

NPI1457377194
Entity TypeOrganization
Primary Taxonomy207W00000X
Legal Business NameERROL O GRANNUM
Location Address1910 S 1ST ST, SUITE 400Mcallen, TX 78503-1255
Mailing Address1910 S 1st St, Suite 400Mcallen, TX 78503-1255 · (956) 687-3937 · Fax (956) 687-3938
Phone(956) 687-3937
Fax(956) 687-3938
Organization SubpartNo
Authorized OfficialErrol Olwyn GrannumOwner · (956) 687-3937
Enumeration DateJuly 14, 2006
Last NPPES UpdateAugust 22, 2020
✔ NPI 1457377194 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyOphthalmologyAllopathic & Osteopathic Physicians
Taxonomy Code207W00000X
License✔ Licensed in TX · K5972
Definition
An ophthalmologist has the knowledge and professional skills needed to provide comprehensive eye and vision care. Ophthalmologists are medically trained to diagnose, monitor and medically or surgically treat all ocular and visual disorders. This includes problems affecting the eye and its component structures, the eyelids, the orbit and the visual pathways. In so doing, an ophthalmologist prescribes vision services, including glasses and contact lenses.
1910 S 1ST ST, Mcallen, TX 78503
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Group Practice 1

Group TaxonomyThis provdier is a business group of one or more individual practitioners, all of who practice with the same area of specialization.193400000X SINGLE SPECIALTY GROUP

Medicare Participation & PECOS CMS

Medicare enrollment, revalidation and the clinicians who bill Medicare through this organization, from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Errol O Grannum is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Medicare Revalidation Due Date

Revalidation due by December 31, 2026

Medicare-enrolled providers and suppliers confirm their enrollment information with CMS on a set cycle, every 5 years for most and every 3 years for medical equipment suppliers. CMS sets the due date for each enrollment.

StateEnrollment IDDue date
StateTexasEnrollment IDO20060815000068Non-DME Part B · Clinic/Group PracticeDue dateDecember 31, 2026
Source: CMS Revalidation Due Date List, October 2026 release.

Clinicians Billing Medicare Through This Organization

Medicare enrollment records show 1 clinician reassigns Medicare billing to Errol O Grannum, which bills Medicare for the services this clinician delivers.

Clinician (1)

Errol Grannum, MD
Ophthalmology
NPI 1508897935
1910 S 1ST ST
Mcallen, TX 78503
(956) 687-3937
✔ PECOS✔ Accepts MedicareSame address

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Errol O Grannum's NPI number?

The NPI number for Errol O Grannum is 1457377194. It was assigned to this organization in the NPPES registry on July 14, 2006.

Where is Errol O Grannum located?

Errol O Grannum is located at 1910 S 1st St Suite 400, Mcallen, TX 78503. The listed phone number is (956) 687-3937.

What is Errol O Grannum's specialty?

The primary specialty registered for this NPI is Ophthalmology with taxonomy code 207W00000X.

Is Errol O Grannum enrolled in Medicare?

Yes. Errol O Grannum is registered in the Medicare PECOS enrollment system.

When is Errol O Grannum's Medicare revalidation due?

According to the CMS Revalidation Due Date List (October 2026 release), the Medicare Non-DME Part B enrollment for this organization (Texas, Clinic/Group Practice) is due for revalidation by December 31, 2026. Medicare providers and suppliers revalidate their enrollment every 5 years, and medical equipment suppliers every 3 years. Confirm current requirements with your Medicare Administrative Contractor.

How many clinicians bill Medicare through Errol O Grannum?

According to the CMS Revalidation Reassignment List (October 2026 release), 1 clinician (Ophthalmology) reassigns their Medicare billing to Errol O Grannum. A reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for the clinician's services. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

When was this NPI record last updated?

The NPPES record for Errol O Grannum was last updated on August 22, 2020. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 6 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.