Active NPI 1508897935 Individual Practitioner Male Practitioner

Dr. Errol Olwyn Grannum , MD

Ophthalmology • Mcallen, TX

✓ Accepts Medicare Assignment

Professional Overview & Biography Verified Profile Summary

Dr. Errol Grannum, MD is a certified Ophthalmology practicing in Mcallen, TX. With approximately 37 years of clinical experience since graduating from Yale University School Of Medicine in 1989, Dr. Grannum delivers high-quality medical care to the local community at 1910 S 1ST ST.

Dr. Grannum is affiliated with Alexander P. Sudarshan Md Pa and accepts Medicare assignment.

Frequently performed procedures and clinical services include established patient problem focused exam of visual system, measurement of corneal pressure, exam of visual field with extended testing. Full Medicare procedure pricing transparency rates and service volume details are listed on this profile.

Practice Location & Contact Primary Location

Practice Address

1910 S 1st St

Mcallen, TX 785031255

Telephone 9566873937

Fax 9566873938

Associated Practice Facility / Clinic

🏢 South Texas Neurological Center, P.a. Facility NPI 1437194875

Medicare Profile & Education

Medical School

Yale University School Of Medicine

Graduation Year

1989

Medicare Assignment

✓ Accepts Assignment

Telehealth Flag

In-Person Only

Specialty Benchmarks & Practice Insights

Comparative analytics for Ophthalmology in Mcallen, TX

Senior Veteran Specialist (>20 Yrs)

Practitioner Clinical Experience

37 Yrs +6.9 yrs vs City Avg

City Avg: 30.1 Yrs

State Avg: 26.2 Yrs

Regional Practice Density

18 Specialists

Practicing in Mcallen, TX (1616 Statewide)

Telehealth Adoption Rate

5.6% Regional Adoption

In-Person Office Visits Only

Medicare Pricing Discount

80.7% Avg Savings

Under CMS Medicare Fee Schedule vs Standard Submitted Charges

Clinical Seniority & Experience Comparison

Dr. Grannum (37 Years) 37 Yrs

Mcallen Specialty Average (30.1 Years) 30.1 Yrs

Performed Procedures & Service Volume

Top Medicare Part B procedures performed by this practitioner

CMS Official Data (2024)

Reporting Year:

HCPCS Code & Description	Services	Patients	Submitted Charge	Medicare Allowed
92012 Established patient problem focused exam of visual system	610	272	$149.77	$78.85
92145 Measurement of corneal pressure	280	175	$25.00	$10.84
92083 Exam of visual field with extended testing	160	144	$225.00	$55.77
92020 Examination of cornea and iris using lens device and slit lamp	123	120	$115.51	$24.06
92133 Imaging of optic nerve	120	118	$300.00	$30.21
99204 New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more	69	69	$300.00	$150.02
92250 Photography of the retina	60	57	$200.00	$31.43
66761 Creation of eye fluid drainage tracts in iris using a laser, per session	38	24	$1257.89	$263.06
65855 Laser repair to improve eye fluid flow	30	21	$1786.67	$215.17
67820 Removal of eyelashes using forceps	25	16	$120.00	$16.67
76514 Ultrasound scan of cornea to determine thickness	19	19	$100.00	$8.91
92201 Extended exam of the back part of the eye with retinal drawing	12	11	$125.00	$22.06

HCPCS Code & Description	Services	Patients	Submitted Charge	Medicare Allowed
92012 Established patient problem focused exam of visual system	659	271	$149.95	$85.98
92145 Measurement of corneal pressure	332	202	$25.00	$11.53
92083 Exam of visual field with extended testing	169	147	$225.00	$59.70
92020 Examination of cornea and iris using lens device and slit lamp	147	144	$119.62	$26.57
92133 Imaging of optic nerve	143	136	$300.00	$33.32
99204 New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more	84	84	$300.00	$159.86
92250 Photography of the retina	50	49	$200.00	$34.58
65855 Laser repair to improve eye fluid flow	31	21	$1800.00	$234.09
76514 Ultrasound scan of cornea to determine thickness	30	30	$100.00	$10.26
67820 Removal of eyelashes using forceps	29	18	$120.00	$18.79
66761 Creation of eye fluid drainage tracts in iris using a laser, per session	20	12	$1400.00	$284.69
92201 Extended exam of the back part of the eye with retinal drawing	12	12	$125.00	$23.73

HCPCS Code & Description	Services	Patients	Submitted Charge	Medicare Allowed
92012 Established patient problem focused exam of visual system	820	321	$150.00	$86.65
92145 Measurement of corneal pressure	303	189	$25.00	$11.40
92083 Exam of visual field with extended testing	260	208	$225.00	$60.78
92020 Examination of cornea and iris using lens device and slit lamp	217	203	$120.00	$27.33
J7351 Injection, bimatoprost, intracameral implant, 1 microgram	211	13	$300.00	$204.91
92133 Imaging of optic nerve	157	151	$300.00	$33.72
99204 New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more	84	84	$300.00	$161.68
92250 Photography of the retina	75	74	$200.00	$34.67
65855 Laser repair to improve eye fluid flow	29	21	$1800.00	$237.23
67820 Removal of eyelashes using forceps	29	23	$120.00	$18.59
76514 Ultrasound scan of cornea to determine thickness	28	28	$100.00	$10.49
66030 Injection of medication into eye	22	13	$250.00	$173.43
66180 Creation of shunt to improve eye fluid flow using tissue graft	17	15	$2200.00	$1070.92

HCPCS Code & Description	Services	Patients	Submitted Charge	Medicare Allowed
92012 Established patient problem focused exam of visual system	771	316	$150.00	$87.55
92083 Exam of visual field with extended testing	290	235	$225.00	$61.44
92145 Measurement of corneal pressure	201	144	$25.00	$12.17
92020 Examination of cornea and iris using lens device and slit lamp	183	180	$120.00	$27.16
92133 Imaging of optic nerve	176	173	$300.00	$33.90
92250 Photography of the retina	129	125	$200.00	$36.50
99204 New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more	98	98	$300.00	$163.39
76514 Ultrasound scan of cornea to determine thickness	45	45	$100.00	$10.73
65855 Laser repair to improve eye fluid flow	44	32	$1800.00	$241.12
67820 Removal of eyelashes using forceps	33	25	$120.00	$20.57
66180 Creation of shunt to improve eye fluid flow using tissue graft	21	18	$2200.00	$1104.92
66761 Creation of eye fluid drainage tracts in iris using a laser, per session	21	15	$1500.00	$294.44
66984 Removal of cataract with insertion of lens	13	11	$3000.00	$528.18

HCPCS Code & Description	Services	Patients	Submitted Charge	Medicare Allowed
92012 Established patient problem focused exam of visual system	570	293	$150.00	$84.94
92083 Exam of visual field with extended testing	219	183	$225.00	$60.22
92020 Examination of cornea and iris using lens device and slit lamp	190	183	$120.00	$26.78
92145 Measurement of corneal pressure	161	135	$25.00	$13.38
92250 Photography of the retina	100	100	$200.00	$41.37
92133 Imaging of optic nerve	96	94	$300.00	$33.67
99204 New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more	80	80	$300.00	$157.80
67820 Removal of eyelashes using forceps	49	37	$120.00	$25.20
76514 Ultrasound scan of cornea to determine thickness	34	34	$100.00	$10.83
65855 Laser repair to improve eye fluid flow	21	16	$1800.00	$237.95
66180 Creation of shunt to improve eye fluid flow using tissue graft	14	13	$2200.00	$1092.03

HCPCS Code & Description	Services	Patients	Submitted Charge	Medicare Allowed
92012 Established patient problem focused exam of visual system	948	433	$150.00	$84.57
92083 Exam of visual field with extended testing	380	291	$225.00	$61.10
92020 Examination of cornea and iris using lens device and slit lamp	255	251	$120.00	$26.63
92133 Imaging of optic nerve	239	223	$300.00	$33.66
92250 Photography of the retina	186	180	$200.00	$45.91
99204 New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more	159	159	$300.00	$158.55
92145 Measurement of corneal pressure	117	112	$25.00	$15.64
76514 Ultrasound scan of cornea to determine thickness	67	67	$100.00	$11.54
65855 Laser repair to improve eye fluid flow	47	36	$1800.00	$239.02
67820 Removal of eyelashes using forceps	45	34	$120.00	$31.56
66984 Removal of cataract with insertion of lens	29	20	$3000.00	$609.29
66180 Creation of shunt to improve eye fluid flow using tissue graft	26	24	$2200.00	$1103.93
66761 Creation of eye fluid drainage tracts in iris using a laser, per session	20	12	$1500.00	$288.54
76519 Ultrasound of eye for determination of lens power	17	16	$250.00	$63.44

HCPCS Code & Description	Services	Patients	Submitted Charge	Medicare Allowed
92012 Established patient problem focused exam of visual system	894	388	$149.70	$79.22
92083 Exam of visual field with extended testing	385	267	$225.00	$57.66
92133 Imaging of optic nerve	366	255	$300.00	$32.18
92020 Examination of cornea and iris using lens device and slit lamp	171	169	$124.68	$24.50
99204 New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more	121	121	$300.00	$149.03
92145 Measurement of corneal pressure	105	84	$25.00	$15.02
92250 Photography of the retina	98	97	$200.00	$50.30
76514 Ultrasound scan of cornea to determine thickness	59	59	$100.00	$13.25
67820 Removal of eyelashes using forceps	49	31	$120.00	$36.66
65855 Laser repair to improve eye fluid flow	47	31	$1800.00	$224.61
66180 Creation of shunt to improve eye fluid flow using tissue graft	27	26	$2200.00	$1041.49

HCPCS Code & Description	Services	Patients	Submitted Charge	Medicare Allowed
92012 Established patient problem focused exam of visual system	932	402	$150.00	$75.90
92133 Imaging of optic nerve	381	273	$300.00	$31.66
92083 Exam of visual field with extended testing	380	272	$225.00	$55.63
92020 Examination of cornea and iris using lens device and slit lamp	231	229	$120.00	$24.09
99204 New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more	149	149	$300.00	$147.14
92250 Photography of the retina	129	128	$200.00	$57.93
92145 Measurement of corneal pressure	120	96	$25.00	$15.13
65855 Laser repair to improve eye fluid flow	59	47	$1800.00	$217.45
76514 Ultrasound scan of cornea to determine thickness	55	55	$100.00	$12.76
66180 Creation of shunt to improve eye fluid flow using tissue graft	40	39	$2200.00	$1001.48
67820 Removal of eyelashes using forceps	24	18	$120.00	$45.15
92275 Recording of retinal electrical responses to external stimuli	13	13	$200.00	$131.34

Medical Specialties & State Licenses

Ophthalmology Primary Specialty

NUCC Taxonomy Code: 207W00000X

State License TX K5972

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.

Hospital & Practice Group Affiliations

Alexander P. Sudarshan Md Pa

1058 E Los Ebanos Blvd, Brownsville, TX 785209988

Phone: 9565414828

Practice Associates & Co-Workers

Healthcare professionals and specialists practicing at this location or sharing practice phone/fax

2 Associated Practitioners

Ruy Mireles Quintanilla

Specialist

NPI 1467458422

Dr. Roberto Arguello , MD

Ophthalmology

NPI 1538130521

Doctor of Medicine (M.D.)

Career & Practice History Timeline

Chronological log of verified NPI updates, location relocations, credentials, and registry changes

6 Historical Events

✅

NPI Profile Active July 08, 2007

NPI status registered as active in NPPES database

📍

Updated Practice Location July 08, 2007

Registered at 1910 S 1ST ST, MCALLEN, TX 785031255 (Tel: 9566873937)

📍

Updated Business Mailing Address July 08, 2007

Registered at 1910 S 1ST ST, MCALLEN, TX 785031255 (Tel: 9566873937)

👤

Provider Name / Credentials Updated July 08, 2007

Recorded as ERROL GRANNUM, MD

🎓

Medical Taxonomy / Specialty Registered (Primary Specialty) July 08, 2007

Ophthalmology (License #K5972 in TX)

🟢

Initial NPI Registration & Enumeration July 05, 2006

First registered as active Individual Practitioner in NPPES Database.

Patient & Community Reviews

Verified patient ratings, medical care experiences, and facility photos

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NPI Administrative Meta

NPI Number: 1508897935

Entity Type:

Individual Provider Physician, Nurse Practitioner, or Solo Healthcare Professional (Type 1 NPI)

Enumeration Date: July 05, 2006

Last Update: July 08, 2007

Sole Proprietor: Yes

Update or Correct Profile

Mailing Address

1910 S 1st St

Mcallen, TX 785031255

Phone: 9566873937

Public Domain Record This profile contains public domain information published by CMS and NPPES under the Freedom of Information Act (FOIA).

⚠️ Medical Disclaimer

This directory listing is for informational purposes only and does not constitute medical advice, diagnosis, or physician endorsement. If you are experiencing a medical emergency, please call 911 immediately.