2026 NPPES data Glaucoma Specialist (Ophthalmology) Physician NPI 1548219934 M.D.
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GREGORY KOUYOUMDJIAN, M.D.

Glaucoma Specialist (Ophthalmology) Physician in LITTLETON, Colorado. 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
240
Medicare Part D claims · 91 beneficiaries · Glaucoma Specialist (Ophthalmology) Physician avg: 3K
Generic prescribing
42%
generic claims · 58% brand-name · higher generic rates reduce patient out-of-pocket costs
MIPS score
93.2026/100
▲ 10 pts above national avg 83.1 · [object Object]
Industry payments
$242.73
10 payments · CMS Open Payments (Sunshine Act)
What the federal data reveals: GREGORY KOUYOUMDJIAN, M.D. is a Glaucoma Specialist (Ophthalmology) Physician ([object Object]) practicing in LITTLETON, Colorado with a Medicare Part D prescribing footprint of 240 claims across 91 beneficiaries — 58% brand-name prescribing . Their CMS MIPS Final Score of 93.2026/100 (national average: 83.1) reflects performance across Quality, Cost, Interoperability, and Improvement Activities . Industry payments of $242.73 across 10 transactions are disclosed under CMS Open Payments (Sunshine Act).

What stands out: GREGORY KOUYOUMDJIAN, M.D. reported a CMS MIPS final score of 93.2026 out of 100, above the 83.1 national average, and filed 240 Medicare Part D claims in 2023. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

Board certification likely (heuristic — not verified)

GREGORY KOUYOUMDJIAN, M.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + MIPS quality reporting + 2 hospital affiliations — signals consistent with board-certified status. For verified board certification, see CertificationMatters.org (the official ABMS public lookup).

GREGORY KOUYOUMDJIAN, M.D. at a glance

High performer (top quartile)

NPI registry status

Active

Issued 05/10/2006

NPI 1548219934

Primary specialty

Glaucoma Specialist (Ophthalmology) Physician

Rare

354 US NPIs in this specialty

Medicare Part D claims

240 92% vs specialty avg

2023 prescription claims

Specialty avg: 2,962

MIPS final score

93.2026/100 10.10260000000001% pts

Exceptional band

vs 83.1 national avg

Specialty distribution in Colorado

How Glaucoma Specialist (Ophthalmology) Physician compares to other specialties among Colorado providers

Colorado providers

Glaucoma Specialist (Ophthalmology) Physician share within Colorado

1. Glaucoma Specialist (Ophthalmology) Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Glaucoma Specialist (Ophthalmology) Physician share within Colorado

Medicare quality performance — MIPS

GREGORY KOUYOUMDJIAN, M.D.'s 2023 MIPS final score plotted against the Glaucoma Specialist (Ophthalmology) Physician national average

High performer (top quartile)
MIPS Final Score
93.2026/100
vs 83.1 national avg · 2023 performance year

MIPS final score (Glaucoma Specialist (Ophthalmology) Physician) — 93.2026/100 vs national avg 83.1

0%100%National avg83%93.2%
MIPS final score (Glaucoma Specialist (Ophthalmology) Physician) — 93.2026/100 vs national avg 83.1

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).

GREGORY KOUYOUMDJIAN, M.D. is a Glaucoma Specialist (Ophthalmology) Physician provider practicing in LITTLETON, Colorado, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: M.D.. NPI: 1548219934. 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.

GREGORY KOUYOUMDJIAN, M.D. appears in the CMS NPPES registry as a Glaucoma Specialist (Ophthalmology) Physician provider holding M.D. credentials at 8381 SOUTHPARK LN, LITTLETON, CO, 80120, with a listed phone of (303) 991-9662. NPI 1548219934 was issued on 05/10/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what KOUYOUMDJIAN 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 240 prescription claims written by this provider, covering 91 Medicare beneficiaries and totaling roughly $34K in drug spend, split 58% brand-name and 42% 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. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 93.2026/100 for the 2023 performance year (Quality 99.1255, Cost 78.5079), compared with the national average of 83.1.

Glaucoma Specialist (Ophthalmology) Physician is a narrow specialty nationwide, with 354 enrolled providers across 42 states and an average of 2,962 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

8381 SOUTHPARK LN
LITTLETON, CO 80120

Provider Details

NPI 1548219934
Specialty Glaucoma Specialist (Ophthalmology) Physician
Credentials M.D.
Gender Male
NPI Issued 05/10/2006

CMS Quality Score (MIPS)

Merit-based Incentive Payment System (MIPS) scores from CMS, 2023 performance year.

93.2026
Final Score
Avg: 83.1
99.1255
Quality
78.5079
Cost

Reporting: Individual

Hospital and facility affiliations

Facilities where GREGORY KOUYOUMDJIAN, M.D. bills Medicare from. Star ratings (1-5) are CMS Hospital Compare's "Hospital overall rating" — a composite of mortality, readmission, patient experience, safety, timely care, and efficient use of medical imaging measures. Source: CMS Care Compare.

GLAUCOMA CONSULTANTS OF COLORADO PC
PARKER, CO
TRAUMA AND EMERGENCY SUBSPECIALTY SURGEONS PLLC
LONE TREE, CO

Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).

Industry payments received (2024) — CMS Open Payments transparency data

The federal Physician Payments Sunshine Act (part of the Affordable Care Act) requires drug and medical-device manufacturers + group purchasing organizations to publicly report payments and other transfers of value to physicians and teaching hospitals. The data below covers 2024 for GREGORY KOUYOUMDJIAN, M.D.. Source: openpaymentsdata.cms.gov.

Total received

$243

Largest payer

Rayner Intraocular Lenses Limited

Most common payment type

Food and Beverage

Industry payments are not necessarily indicators of bias — they include research funding, consulting fees for evidence-based work, royalties for inventions, food at conferences, and similar items. The disclosure exists for transparency. Read our methodology for how we interpret this data.

Brand vs generic prescribing mix · Brand-heavy

GREGORY KOUYOUMDJIAN, M.D. — brand share 58.0%
Specialty average (est.)

58% brand-name claims vs 42% generic, on 240 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.

240
Total Claims
$34K
Total Drug Cost
91
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
379
Total Day Supply
9,944
Brand vs Generic
58% brand / 42% generic
Brand Drug Cost
$31K
Generic Drug Cost
$4K

Patient Demographics

Average Patient Age
73.5 years
Avg HCC Risk Score
1.11
Gender Split
64% female / 36% male

Top Prescribed Drugs (Medicare Part D)

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

Drug Claims
Prednisolone Acetate
59
Timolol Maleate
22
Dorzolamide Hcl
17
Flarex
Fluorometholone Acetate
17
Latanoprost
17
Fluorometholone
16
Tobramycin-Dexamethasone
Tobramycin/Dexamethasone
14

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

Glaucoma Specialist (Ophthalmology) Physician Overview

How GREGORY KOUYOUMDJIAN, M.D. fits within the Glaucoma Specialist (Ophthalmology) Physician landscape nationally.

354
Glaucoma Specialist (Ophthalmology) Physician Providers in US
42
States with Glaucoma Specialist (Ophthalmology) Physician
2,962
Avg Claims per Provider

GREGORY KOUYOUMDJIAN, M.D.'s 240 claims are below the specialty average of 2,962.

Nearby Glaucoma Specialist (Ophthalmology) Physician Providers in Colorado

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

Compare Glaucoma Specialist (Ophthalmology) Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is GREGORY KOUYOUMDJIAN, M.D.'s specialty?
GREGORY KOUYOUMDJIAN, M.D. specializes in Glaucoma Specialist (Ophthalmology) Physician and practices in LITTLETON, Colorado. Credentials: M.D..
How much does GREGORY KOUYOUMDJIAN, M.D. prescribe under Medicare Part D?
In 2023, GREGORY KOUYOUMDJIAN, M.D. wrote 240 Medicare Part D claims totaling $34K in drug costs for 91 beneficiaries.
What is GREGORY KOUYOUMDJIAN, M.D.'s Medicare quality score?
GREGORY KOUYOUMDJIAN, M.D. has a CMS MIPS Final Score of 93.2026/100 (Quality: 99.1255, Cost: 78.5079). The national average MIPS Final Score is 83.1. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is GREGORY KOUYOUMDJIAN, M.D. located?
GREGORY KOUYOUMDJIAN, M.D. is located at 8381 SOUTHPARK LN, LITTLETON, CO, 80120. Phone: (303) 991-9662.
What is GREGORY KOUYOUMDJIAN, M.D.'s NPI number?
GREGORY KOUYOUMDJIAN, M.D.'s National Provider Identifier (NPI) is 1548219934, issued on 05/10/2006.
Does GREGORY KOUYOUMDJIAN, M.D. prescribe more brand-name or generic drugs?
GREGORY KOUYOUMDJIAN, M.D.'s prescribing is 58% brand-name and 42% generic drugs by claim count, with $31K in brand drug costs.
How many Glaucoma Specialist (Ophthalmology) Physician providers are there in the US?
There are 354 Glaucoma Specialist (Ophthalmology) Physician providers across 42 states in the US. The average Glaucoma Specialist (Ophthalmology) Physician provider writes 2,962 Medicare Part D claims per year.
What drugs does GREGORY KOUYOUMDJIAN, M.D. prescribe most often?
Based on 2023 Medicare Part D data, GREGORY KOUYOUMDJIAN, M.D.'s most frequently prescribed drugs include Prednisolone Acetate, Timolol Maleate, Dorzolamide Hcl. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does GREGORY KOUYOUMDJIAN, M.D. accept Medicare?
GREGORY KOUYOUMDJIAN, M.D. appears in CMS Medicare data with 240 Part D claims and 91 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify GREGORY KOUYOUMDJIAN, M.D.'s credentials?
GREGORY KOUYOUMDJIAN, M.D.'s NPI is 1548219934 with credentials M.D.. 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.
Quality Performance
CMS Merit-based Incentive Payment System (MIPS) — 2023 performance year.
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