Active NPI 1386634400 Individual Practitioner Male Practitioner

Dr. John F Warren , MD

Ophthalmology • Greenfield, MA

✓ Accepts Medicare Assignment

Professional Overview & Biography Verified Profile Summary

Dr. John Warren, MD is a certified Ophthalmology practicing in Greenfield, MA. With approximately 29 years of clinical experience since graduating from Stanford University School Of Medicine in 1997, Dr. Warren delivers high-quality medical care to the local community at 33 RIDDELL ST.

Dr. Warren is affiliated with Longwood Eye Llc and accepts Medicare assignment.

Frequently performed procedures and clinical services include measurement of corneal curvature and depth of eye, removal of cataract with insertion of lens, imaging of retina. Full Medicare procedure pricing transparency rates and service volume details are listed on this profile.

Practice Location & Contact Primary Location

Practice Address

33 Riddell St

Greenfield, MA 01301

Telephone 4137747016

Fax 4137737596

Associated Practice Facility / Clinic

🏢 Franklin Eye Care Associates, Llc Facility NPI 1083670574

Medicare Profile & Education

Medical School

Stanford University School Of Medicine

Graduation Year

1997

Medicare Assignment

✓ Accepts Assignment

Telehealth Flag

In-Person Only

Specialty Benchmarks & Practice Insights

Comparative analytics for Ophthalmology in Greenfield, MA

Senior Veteran Specialist (>20 Yrs)

Practitioner Clinical Experience

29 Yrs -5.5 yrs vs City Avg

City Avg: 34.5 Yrs

State Avg: 30.8 Yrs

Regional Practice Density

2 Specialists

Practicing in Greenfield, MA (841 Statewide)

Telehealth Adoption Rate

0.0% Regional Adoption

In-Person Office Visits Only

Medicare Pricing Discount

71.1% Avg Savings

Under CMS Medicare Fee Schedule vs Standard Submitted Charges

Clinical Seniority & Experience Comparison

Dr. Warren (29 Years) 29 Yrs

Greenfield Specialty Average (34.5 Years) 34.5 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
92136 Measurement of corneal curvature and depth of eye	987	360	$280.28	$27.96
66984 Removal of cataract with insertion of lens	619	348	$2400.00	$560.65
92134 Imaging of retina	542	518	$110.00	$42.38
92014 Established patient complete exam of visual system	538	507	$350.00	$135.45
92025 Ct scan of cornea	333	225	$100.00	$39.19
68841 Insertion of drug delivery implant into tear duct of eye	213	141	$70.00	$17.18
99204 New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more	207	207	$450.00	$177.14
92012 Established patient problem focused exam of visual system	136	104	$240.00	$96.34
92133 Imaging of optic nerve	95	89	$100.00	$37.55
66821 Removal of recurring cataract in lens capsule using a laser	72	72	$1222.22	$468.00
92083 Exam of visual field with extended testing	50	50	$200.00	$68.60
66991 Extracapsular removal of cataract with insertion of artificial lens and insertion of drainage device in front chamber of eye	45	26	$2400.00	$675.88
66982 Complex removal of cataract with insertion of prosthetic lens	40	31	$3000.00	$751.22
92004 New patient complete exam of visual system	23	23	$402.00	$160.00
92286 Imaging of front third of eye using a special microscope	13	13	$105.00	$42.39

HCPCS Code & Description	Services	Patients	Submitted Charge	Medicare Allowed
92136 Measurement of corneal curvature and depth of eye	1,097	375	$280.00	$26.05
66984 Removal of cataract with insertion of lens	597	336	$2400.00	$520.86
92014 Established patient complete exam of visual system	500	473	$339.08	$130.52
92134 Imaging of retina	467	448	$110.00	$41.11
99204 New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more	257	257	$450.00	$168.28
92025 Ct scan of cornea	214	175	$100.00	$37.41
68841 Insertion of drug delivery implant into tear duct of eye	210	116	$70.00	$16.50
92012 Established patient problem focused exam of visual system	144	103	$240.00	$92.70
66821 Removal of recurring cataract in lens capsule using a laser	70	70	$1222.86	$434.32
92133 Imaging of optic nerve	69	68	$100.00	$36.07
66991 Extracapsular removal of cataract with insertion of artificial lens and insertion of drainage device in front chamber of eye	54	30	$2400.00	$630.13
92083 Exam of visual field with extended testing	48	48	$200.00	$65.28
66982 Complex removal of cataract with insertion of prosthetic lens	33	25	$3000.00	$723.00
92004 New patient complete exam of visual system	25	25	$402.00	$154.64

HCPCS Code & Description	Services	Patients	Submitted Charge	Medicare Allowed
92136 Measurement of corneal curvature and depth of eye	1,011	345	$280.00	$28.21
66984 Removal of cataract with insertion of lens	528	301	$2400.00	$538.01
92014 Established patient complete exam of visual system	490	457	$290.00	$132.79
92134 Imaging of retina	318	311	$110.00	$42.52
92012 Established patient problem focused exam of visual system	203	128	$240.00	$93.86
68841 Insertion of drug delivery implant into tear duct of eye	188	109	$70.00	$16.74
99204 New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more	166	166	$450.00	$173.15
92004 New patient complete exam of visual system	102	102	$402.00	$157.71
92133 Imaging of optic nerve	79	76	$100.00	$36.87
66991 Extracapsular removal of cataract with insertion of artificial lens and insertion of drainage device in front chamber of eye	68	38	$2393.63	$686.37
66821 Removal of recurring cataract in lens capsule using a laser	65	64	$1230.77	$444.18
92083 Exam of visual field with extended testing	57	55	$200.00	$66.53
92025 Ct scan of cornea	48	43	$100.00	$36.37
66982 Complex removal of cataract with insertion of prosthetic lens	18	14	$3000.00	$744.55

HCPCS Code & Description	Services	Patients	Submitted Charge	Medicare Allowed
92136 Measurement of corneal curvature and depth of eye	735	264	$280.00	$30.55
92014 Established patient complete exam of visual system	542	515	$290.00	$135.26
66984 Removal of cataract with insertion of lens	475	270	$2400.00	$550.70
0356T Insertion of drug delivery implant into tear ducts	312	179	$600.00	$86.61
92012 Established patient problem focused exam of visual system	273	200	$240.00	$94.43
92134 Imaging of retina	205	201	$110.00	$43.36
92004 New patient complete exam of visual system	111	111	$402.00	$160.67
92133 Imaging of optic nerve	92	90	$100.00	$38.39
66821 Removal of recurring cataract in lens capsule using a laser	90	88	$1200.00	$451.10
99204 New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more	76	76	$450.00	$175.05
92083 Exam of visual field with extended testing	48	47	$200.00	$68.14
92025 Ct scan of cornea	31	31	$100.00	$38.22
66982 Complex removal of cataract with insertion of prosthetic lens	28	22	$2921.43	$772.60
0191T Internal insertion of eye fluid drainage device	20	12	$1000.00	$371.50

HCPCS Code & Description	Services	Patients	Submitted Charge	Medicare Allowed
92014 Established patient complete exam of visual system	716	672	$290.00	$134.65
92136 Measurement of corneal curvature and depth of eye	530	202	$280.00	$33.36
66984 Removal of cataract with insertion of lens	339	199	$2400.00	$556.62
92012 Established patient problem focused exam of visual system	237	181	$240.00	$94.09
92133 Imaging of optic nerve	135	134	$106.52	$37.90
92083 Exam of visual field with extended testing	103	102	$200.00	$68.05
0356T Insertion of drug delivery implant into tear ducts	99	58	$600.00	$83.37
92134 Imaging of retina	95	92	$112.21	$43.69
66821 Removal of recurring cataract in lens capsule using a laser	79	76	$1134.18	$439.42
99204 New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more	73	73	$450.00	$174.90
99214 Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more	62	62	$270.94	$115.99
92250 Photography of the retina	43	43	$142.44	$48.04
92004 New patient complete exam of visual system	29	29	$402.00	$156.78
0191T Internal insertion of eye fluid drainage device	25	16	$1000.00	$356.26
92025 Ct scan of cornea	19	18	$100.00	$39.15
66982 Complex removal of cataract with insertion of prosthetic lens	18	15	$2777.78	$681.88
99213 Established patient office or other outpatient visit, typically 15 minutes	14	13	$179.00	$80.23
92286 Imaging of front third of eye using a special microscope	11	11	$105.00	$41.89

HCPCS Code & Description	Services	Patients	Submitted Charge	Medicare Allowed
92014 Established patient complete exam of visual system	875	830	$290.00	$134.11
92136 Measurement of corneal curvature and depth of eye	591	294	$280.00	$36.75
66984 Removal of cataract with insertion of lens	471	266	$2400.00	$651.10
92012 Established patient problem focused exam of visual system	352	273	$220.91	$93.71
92133 Imaging of optic nerve	211	207	$180.00	$37.27
92083 Exam of visual field with extended testing	184	180	$200.00	$68.65
99204 New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more	102	102	$450.00	$172.72
66821 Removal of recurring cataract in lens capsule using a laser	99	98	$1107.07	$426.45
92004 New patient complete exam of visual system	54	54	$381.78	$158.62
92134 Imaging of retina	53	52	$180.00	$43.34
92250 Photography of the retina	40	40	$175.00	$54.24
0191T Internal insertion of eye fluid drainage device	32	18	$1000.00	$352.42
66982 Complex removal of cataract with insertion of prosthetic lens	21	16	$2800.00	$806.73
92025 Ct scan of cornea	19	15	$100.00	$40.29
68761 Closure of tear duct opening using plug	17	12	$847.06	$190.09
92286 Imaging of front third of eye using a special microscope	16	14	$153.13	$41.10

HCPCS Code & Description	Services	Patients	Submitted Charge	Medicare Allowed
92014 Established patient complete exam of visual system	1,044	977	$290.00	$132.63
92136 Measurement of corneal curvature and depth of eye	661	307	$280.00	$39.57
92012 Established patient problem focused exam of visual system	502	401	$210.00	$92.05
66984 Removal of cataract with insertion of lens	483	291	$2400.00	$645.82
92133 Imaging of optic nerve	228	223	$180.00	$37.67
92083 Exam of visual field with extended testing	167	167	$200.00	$68.07
99204 New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more	108	108	$447.17	$172.05
66821 Removal of recurring cataract in lens capsule using a laser	99	96	$1147.47	$424.21
92134 Imaging of retina	68	66	$180.00	$43.71
92250 Photography of the retina	59	59	$175.00	$60.66
0191T Internal insertion of eye fluid drainage device	39	23	$1000.00	$373.19
92004 New patient complete exam of visual system	32	32	$350.00	$158.59
66982 Complex removal of cataract with insertion of prosthetic lens	25	20	$2800.00	$784.98
92286 Imaging of front third of eye using a special microscope	21	19	$200.00	$40.65
99214 Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more	15	15	$268.00	$112.53
76519 Ultrasound of eye for determination of lens power	13	11	$255.00	$35.87

HCPCS Code & Description	Services	Patients	Submitted Charge	Medicare Allowed
92014 Established patient complete exam of visual system	1,032	933	$290.00	$128.34
92136 Measurement of corneal curvature and depth of eye	628	299	$280.00	$43.43
92012 Established patient problem focused exam of visual system	564	411	$210.00	$88.25
66984 Removal of cataract with insertion of lens	334	207	$2400.00	$636.03
92133 Imaging of optic nerve	217	213	$180.00	$37.30
92083 Exam of visual field with extended testing	159	155	$197.11	$67.51
99204 New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more	102	102	$433.00	$165.85
66821 Removal of recurring cataract in lens capsule using a laser	100	97	$984.00	$402.72
92134 Imaging of retina	82	78	$180.00	$42.66
92250 Photography of the retina	71	71	$175.00	$69.41
92004 New patient complete exam of visual system	30	30	$350.00	$151.47
92286 Imaging of front third of eye using a special microscope	23	23	$200.00	$40.15
66982 Complex removal of cataract with insertion of prosthetic lens	16	12	$2800.00	$813.88
76514 Ultrasound scan of cornea to determine thickness	15	15	$100.00	$15.03
99203 New patient office or other outpatient visit with low level of medical decision making, if using time, 30 minutes or more	15	15	$290.00	$111.63
0191T Internal insertion of eye fluid drainage device	14	12	$1000.00	$451.58

Medical Specialties & State Licenses

Ophthalmology Primary Specialty

NUCC Taxonomy Code: 207W00000X

State License MA 223233

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

Longwood Eye Llc

180 Daggett Dr, West Springfield, MA 010894667

Phone: 4134524111

Practice Associates & Co-Workers

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

7 Associated Practitioners

Dr. Andrew Walkowiak , OD

Optometrist

NPI 1053301135

Doctor of Optometry

Dr. Natasha Odom-Fern , OD

Optometrist

NPI 1225927452

Doctor of Optometry

Dr. Rahul Patel , MD

Ophthalmology

NPI 1548311319

Doctor of Medicine (M.D.)

Dr. Melissa Butler , OD OPTOMETRIST

Optometrist

NPI 1699818922

ODOPTOMETRIST

Dr. Karen Gingras , OD

Optometrist

NPI 1720309347

Doctor of Optometry

Dr. Kristin Glavine , OD

Optometrist

NPI 1962632091

Doctor of Optometry

Career & Practice History Timeline

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

6 Historical Events

✅

NPI Profile Active January 14, 2011

NPI status registered as active in NPPES database

📍

Updated Practice Location January 14, 2011

Registered at 33 RIDDELL ST, GREENFIELD, MA 01301 (Tel: 4137747016)

📍

Updated Business Mailing Address January 14, 2011

Registered at 33 RIDDELL ST, GREENFIELD, MA 01301 (Tel: 4137747016)

👤

Provider Name / Credentials Updated January 14, 2011

Recorded as JOHN WARREN, MD

🎓

Medical Taxonomy / Specialty Registered (Primary Specialty) January 14, 2011

Ophthalmology (License #223233 in MA)

🟢

Initial NPI Registration & Enumeration October 28, 2005

First registered as active Individual Practitioner in NPPES Database.

Patient & Community Reviews

Verified patient ratings, medical care experiences, and facility photos

0 Reviews

No patient reviews submitted yet for Dr. John Warren. Be the first to share your experience!

Only verified registered users can submit ratings, post feedback, and upload facility photos.

NPI Administrative Meta

NPI Number: 1386634400

Entity Type:

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

Enumeration Date: October 28, 2005

Last Update: March 07, 2023

Sole Proprietor: No

Update or Correct Profile

Mailing Address

33 Riddell St

Greenfield, MA 01301

Phone: 4137747016

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.