Browse Health
Ophthalmologist (eyes)
18 years of experience
Accepting new patients
License & Identifications

A medical license is required for a doctor to practice medicine in a particular state. Requirements vary by state but most require, at a minimum, post-graduate training in the doctor’s specific specialty. An NPI number is a national identifier unique to an individual health care provider and is managed by the Center for Medicare & Medicaid Services (CMS).

Learn more about Dr. Errol Grannum:

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  1. Qualifications
  2. What's important to you

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Patient Reviews

Patient comments (0)

The overall average patient rating of Dr. Errol Grannum is Excellent. Dr. Grannum has been reviewed by 2 patients who have provided 0 comments. The rating is 5 out of 5 stars.

Specialties & Research

  • He has special expertise in 1 area:
  • Glaucoma

Education & Awards

Dr. Grannum graduated from Yale University, New Haven.


Dr. Grannum has 8 hospital affiliations:

  • Valley Baptist Medical Center 
  • Doctors Hospital Renaissance - Edinburg 


  • Spanish
  • English

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Additional Information
Dr. Errol Olwyn Grannum MD is a male Ophthalmologist, has 18 years of experience and practices in Ophthalmology.
Where does Dr. Errol O. Grannum practice?
Dr. Errol Grannum has 3 office locations.
Dr. Errol Grannum practices Ophthalmology near McAllen, TX.
Additional practice locations include: Harlingen, TX.
See McAllen Ophthalmologists.