2026 NPPES data Ophthalmology Physician NPI 1881601581 MD
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JOHN HORNBY, MD

Ophthalmology Physician in OLD SAYBROOK, Connecticut. CMS National Plan and Provider Enumeration System profile including specialty classification, practice address, and Medicare prescribing data when reported.

Federal data — no proprietary rating. PlainDoctor publishes the actual CMS NPPES and Medicare records — NPI registration, specialty, practice location, and prescribing data — without a composite score or editorial opinion on top. Every field traces to a federal source.
Prescribing volume
330
Medicare Part D claims · 107 beneficiaries · Ophthalmology Physician avg: 1K
Generic prescribing
87%
generic claims · 13% brand-name · higher generic rates reduce patient out-of-pocket costs
What the federal data reveals: JOHN HORNBY, MD is a Ophthalmology Physician ([object Object]) practicing in OLD SAYBROOK, Connecticut with a Medicare Part D prescribing footprint of 330 claims across 107 beneficiaries — 13% brand-name prescribing .

What stands out: JOHN HORNBY, MD filed 330 Medicare Part D claims in 2023 across OLD SAYBROOK, Connecticut. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

Board-eligible specialty (heuristic — not verified)

JOHN HORNBY, MD practices in an ABMS-board-eligible specialty but we don't have enough CMS-participation signals to confirm active board-certified status. Consult CertificationMatters.org (the official ABMS public lookup).

JOHN HORNBY, MD at a glance

Quality data not reported

NPI registry status

Active

Issued 08/02/2006

NPI 1881601581

Primary specialty

Ophthalmology Physician

Mid-sized

22,090 US NPIs in this specialty

Medicare Part D claims

330 77% vs specialty avg

2023 prescription claims

Specialty avg: 1,420

Specialty distribution in Connecticut

How Ophthalmology Physician compares to other specialties among Connecticut providers

Connecticut providers

Ophthalmology Physician share within Connecticut

1. Ophthalmology Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Ophthalmology Physician share within Connecticut

Specialty board-certification context

Estimated specialty board-certified rate — Ophthalmology Physician (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Ophthalmology Physician ABMS/AOA estimate

Est. board-certified rate (Ophthalmology Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Ophthalmology Physician) — ABMS / AOA estimate

The Merit-based Incentive Payment System (MIPS) scores providers 0–100 across four performance categories: Quality, Cost, Promoting Interoperability, and Improvement Activities, weighted under 42 CFR §414.1380. Reporting is voluntary for many small practices, so absence of a MIPS score is not a quality signal.

Board certification through an ABMS or AOA member board signals voluntary post-licensure examination plus continuous Maintenance of Certification cycles. Verify any individual provider's status through certificationmatters.org (ABMS) or osteopathic.org (AOA).

JOHN HORNBY, MD is a Ophthalmology Physician provider practicing in OLD SAYBROOK, Connecticut, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: MD. NPI: 1881601581. This profile includes practice location, specialty classification, and organizational affiliations from the CMS provider registry. Provider information is self-reported to CMS and updated monthly.

JOHN HORNBY, MD appears in the CMS NPPES registry as a Ophthalmology Physician provider holding MD credentials at 48 MAIN ST, OLD SAYBROOK, CT, 06475, with a listed phone of (860) 388-1251. NPI 1881601581 was issued on 08/02/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what HORNBY most recently submitted to CMS rather than a vetted directory listing, which is why patients should always confirm the practice is still at this location before scheduling.

Medicare Part D records for calendar year 2023 show 330 prescription claims written by this provider, covering 107 Medicare beneficiaries and totaling roughly $21K in drug spend, split 13% brand-name and 87% generic by claim count. These figures capture only Medicare Part D — commercial insurance, Medicaid, and cash-pay prescriptions are not included, and any drug-beneficiary cell under 11 is suppressed by CMS for patient privacy.

Ophthalmology Physician is a mid-sized specialty nationwide, with 22,090 enrolled providers across 56 states and an average of 1,420 Part D claims per prescriber, so the context for interpreting these metrics differs meaningfully from a primary-care baseline. Important: PlainDoctor is a directory of publicly available government data, not medical advice, a malpractice database, or a quality rating. Inclusion here does not imply a recommendation, and absence of complaints or sanctions on this page does not mean none exist — always verify credentials through the NPPES NPI Registry, your state medical board, and the ABMS or AOA before making healthcare decisions.

Practice Address

48 MAIN ST
OLD SAYBROOK, CT 06475

Provider Details

NPI 1881601581
Specialty Ophthalmology Physician
Credentials MD
Gender Male
NPI Issued 08/02/2006

Brand vs generic prescribing mix · Typical

JOHN HORNBY, MD — brand share 13.0%
Specialty average (est.)

13% brand-name claims vs 87% generic, on 330 2023 Medicare Part D claims.

The federal Medicare Part D Generic Dispensing Rate national benchmark sits near 90% generic / 10% brand for primary-care prescribers, per CMS Office of the Actuary 2024 estimates. Higher brand share is common in specialty prescribing where generic equivalents are not available.

Medicare Part D Prescribing Data

CMS Medicare Part D prescriber-level data for calendar year 2023.

330
Total Claims
$21K
Total Drug Cost
107
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
658
Total Day Supply
19,466
Brand vs Generic
13% brand / 87% generic
Brand Drug Cost
$11K
Generic Drug Cost
$10K
Antibiotic Claims
161

Patient Demographics

Average Patient Age
78.2 years
Avg HCC Risk Score
0.97
Gender Split
58% female / 42% male
Age Distribution
<65: 0, 65-74: 38, 75-84: 47, 85+: 22

Top Prescribed Drugs (Medicare Part D)

Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.

Drug Claims
Doxycycline Hyclate
138
Latanoprost
84
Timolol Maleate
21
Acyclovir
20
Doxycycline Monohydrate
17
Dorzolamide-Timolol
Dorzolamide Hcl/Timolol Maleat
15
Lumigan
Bimatoprost
13

* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.

Ophthalmology Physician Overview

How JOHN HORNBY, MD fits within the Ophthalmology Physician landscape nationally.

22,090
Ophthalmology Physician Providers in US
56
States with Ophthalmology Physician
1,420
Avg Claims per Provider

JOHN HORNBY, MD's 330 claims are below the specialty average of 1,420.

Nearby Ophthalmology Physician Providers in Connecticut

Other clinicians with the same primary specialty enrolled in Connecticut, drawn from the same CMS NPPES roster as HORNBY.

Compare Ophthalmology Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is JOHN HORNBY, MD's specialty?
JOHN HORNBY, MD specializes in Ophthalmology Physician and practices in OLD SAYBROOK, Connecticut. Credentials: MD.
How much does JOHN HORNBY, MD prescribe under Medicare Part D?
In 2023, JOHN HORNBY, MD wrote 330 Medicare Part D claims totaling $21K in drug costs for 107 beneficiaries.
Where is JOHN HORNBY, MD located?
JOHN HORNBY, MD is located at 48 MAIN ST, OLD SAYBROOK, CT, 06475. Phone: (860) 388-1251.
What is JOHN HORNBY, MD's NPI number?
JOHN HORNBY, MD's National Provider Identifier (NPI) is 1881601581, issued on 08/02/2006.
Does JOHN HORNBY, MD prescribe more brand-name or generic drugs?
JOHN HORNBY, MD's prescribing is 13% brand-name and 87% generic drugs by claim count, with $11K in brand drug costs.
How many Ophthalmology Physician providers are there in the US?
There are 22,090 Ophthalmology Physician providers across 56 states in the US. The average Ophthalmology Physician provider writes 1,420 Medicare Part D claims per year.
What drugs does JOHN HORNBY, MD prescribe most often?
Based on 2023 Medicare Part D data, JOHN HORNBY, MD's most frequently prescribed drugs include Doxycycline Hyclate, Latanoprost, Timolol Maleate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does JOHN HORNBY, MD accept Medicare?
JOHN HORNBY, MD appears in CMS Medicare data with 330 Part D claims and 107 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify JOHN HORNBY, MD's credentials?
JOHN HORNBY, MD's NPI is 1881601581 with credentials MD. You can verify this through the NPPES NPI Registry, check state medical board records, and confirm board certification through the ABMS or AOA.

Data Sources

Provider Directory
CMS National Plan and Provider Enumeration System (NPPES), download.cms.gov/nppes, updated monthly. Contains NPI, specialty, credentials, and practice location.
Specialty Classification
NUCC Health Care Provider Taxonomy (nucc.org), the industry standard for classifying provider specialties in Medicare and Medicaid billing.
Prescribing Data
CMS Medicare Part D Prescriber Public Use File (2023). Includes claims, drug costs, beneficiaries, and opioid prescribing rates.
Limitations
Provider data is self-reported to CMS. Prescribing data reflects Medicare Part D only and does not include commercial insurance, Medicaid, or cash prescriptions. Claims below 11 beneficiaries are suppressed by CMS for privacy.

See our complete data methodology for details on how we collect and process government data.

Data as of April 2026 (NPPES) / 2023 (Medicare Part D). Source: Centers for Medicare & Medicaid Services (CMS).

Disclaimer: Data from CMS NPPES and Medicare Part D. PlainDoctor does not rate or rank providers. Provider information is self-reported and may not be current. Always verify information directly with the provider. About · Methodology