2026 NPPES data Glaucoma Specialist (Ophthalmology) Physician NPI 1255391801 M.D.
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GREGORY OSMUNDSON, M.D.

Glaucoma Specialist (Ophthalmology) Physician in SIOUX FALLS, South Dakota. 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
839
Medicare Part D claims · 252 beneficiaries · Glaucoma Specialist (Ophthalmology) Physician avg: 3K
Generic prescribing
69%
generic claims · 31% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$1.0K
10 payments · CMS Open Payments (Sunshine Act)
What the federal data reveals: GREGORY OSMUNDSON, M.D. is a Glaucoma Specialist (Ophthalmology) Physician ([object Object]) practicing in SIOUX FALLS, South Dakota with a Medicare Part D prescribing footprint of 839 claims across 252 beneficiaries — 31% brand-name prescribing . Industry payments of $1.0K across 10 transactions are disclosed under CMS Open Payments (Sunshine Act).

What the federal data shows

GREGORY OSMUNDSON, M.D. filed 839 Medicare Part D claims in 2023 as a Glaucoma Specialist (Ophthalmology) Physician in SIOUX FALLS, South Dakota, prescribing 69% generic.

839
Part D claims, 2023
69%
generic prescribing
Likely
board-certified (heuristic)

Every figure on this page comes straight from federal CMS records (NPPES, Medicare Part D, MIPS, Open Payments) — no proprietary rating or editorial opinion is applied.

Board certification likely (heuristic — not verified)

GREGORY OSMUNDSON, M.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 1 hospital affiliation — signals consistent with board-certified status. For verified board certification, see CertificationMatters.org (the official ABMS public lookup).

GREGORY OSMUNDSON, M.D. at a glance

Quality data not reported

NPI registry status

Active

Issued 03/27/2006

NPI 1255391801

Primary specialty

Glaucoma Specialist (Ophthalmology) Physician

Rare

354 US NPIs in this specialty

Medicare Part D claims

839 72% vs specialty avg

2023 prescription claims

Specialty avg: 2,962

Specialty distribution in South Dakota

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

South Dakota providers

Glaucoma Specialist (Ophthalmology) Physician share within South Dakota

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

Specialty board-certification context

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

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

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

0%100%78%
Est. board-certified rate (Glaucoma Specialist (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).

GREGORY OSMUNDSON, M.D. is a Glaucoma Specialist (Ophthalmology) Physician provider practicing in SIOUX FALLS, South Dakota, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: M.D.. NPI: 1255391801. 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 OSMUNDSON, M.D. appears in the CMS NPPES registry as a Glaucoma Specialist (Ophthalmology) Physician provider holding M.D. credentials at 6601 S MINNESOTA AVE, SIOUX FALLS, SD, 57108, with a listed phone of (605) 336-6294. NPI 1255391801 was issued on 03/27/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what OSMUNDSON 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 839 prescription claims written by this provider, covering 252 Medicare beneficiaries and totaling roughly $28K in drug spend, split 31% brand-name and 69% 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.

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

6601 S MINNESOTA AVE
SIOUX FALLS, SD 57108

Provider Details

NPI 1255391801
Specialty Glaucoma Specialist (Ophthalmology) Physician
Credentials M.D.
Gender Male
NPI Issued 03/27/2006

Hospital and facility affiliations

Facilities where GREGORY OSMUNDSON, 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.

OPHTHALMOLOGY LTD
MITCHELL, SD

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 OSMUNDSON, M.D.. Source: openpaymentsdata.cms.gov.

Total received

$1.0K

Largest payer

Alcon Vision LLC

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 · Above average

GREGORY OSMUNDSON, M.D. — brand share 31.0%
Specialty average (est.)

31% brand-name claims vs 69% generic, on 839 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.

839
Total Claims
$28K
Total Drug Cost
252
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
1,057
Total Day Supply
27,124
Brand vs Generic
31% brand / 69% generic
Brand Drug Cost
$17K
Generic Drug Cost
$11K

Patient Demographics

Average Patient Age
77.1 years
Avg HCC Risk Score
0.99
Gender Split
53% female / 47% 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
Ketorolac Tromethamine
226
Prednisolone Acetate
225
Ofloxacin
218
Latanoprost
78
Dorzolamide-Timolol
Dorzolamide Hcl/Timolol Maleat
31
Timolol Maleate
15

* 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 OSMUNDSON, 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 OSMUNDSON, M.D.'s 839 claims are below the specialty average of 2,962.

Nearby Glaucoma Specialist (Ophthalmology) Physician Providers in South Dakota

Other clinicians with the same primary specialty enrolled in South Dakota, drawn from the same CMS NPPES roster as OSMUNDSON.

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

Frequently Asked Questions

What is GREGORY OSMUNDSON, M.D.'s specialty?
GREGORY OSMUNDSON, M.D. specializes in Glaucoma Specialist (Ophthalmology) Physician and practices in SIOUX FALLS, South Dakota. Credentials: M.D..
How much does GREGORY OSMUNDSON, M.D. prescribe under Medicare Part D?
In 2023, GREGORY OSMUNDSON, M.D. wrote 839 Medicare Part D claims totaling $28K in drug costs for 252 beneficiaries.
Where is GREGORY OSMUNDSON, M.D. located?
GREGORY OSMUNDSON, M.D. is located at 6601 S MINNESOTA AVE, SIOUX FALLS, SD, 57108. Phone: (605) 336-6294.
What is GREGORY OSMUNDSON, M.D.'s NPI number?
GREGORY OSMUNDSON, M.D.'s National Provider Identifier (NPI) is 1255391801, issued on 03/27/2006.
Does GREGORY OSMUNDSON, M.D. prescribe more brand-name or generic drugs?
GREGORY OSMUNDSON, M.D.'s prescribing is 31% brand-name and 69% generic drugs by claim count, with $17K 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 OSMUNDSON, M.D. prescribe most often?
Based on 2023 Medicare Part D data, GREGORY OSMUNDSON, M.D.'s most frequently prescribed drugs include Ketorolac Tromethamine, Prednisolone Acetate, Ofloxacin. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does GREGORY OSMUNDSON, M.D. accept Medicare?
GREGORY OSMUNDSON, M.D. appears in CMS Medicare data with 839 Part D claims and 252 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify GREGORY OSMUNDSON, M.D.'s credentials?
GREGORY OSMUNDSON, M.D.'s NPI is 1255391801 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.
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