2026 NPPES data Corneal and Contact Management Optometrist NPI 1679534705 O.D.
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GREGORY ZELL, O.D.

Corneal and Contact Management Optometrist in MISSOULA, Montana. 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
15
Medicare Part D claims · Corneal and Contact Management Optometrist avg: 235
Generic prescribing
27%
generic claims · 73% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$100
1 payments · CMS Open Payments (Sunshine Act)

What the federal data shows

GREGORY ZELL, O.D. filed 15 Medicare Part D claims in 2023 as a Corneal and Contact Management Optometrist in MISSOULA, Montana, prescribing 27% generic.

15
Part D claims, 2023
27%
generic prescribing
$100
industry payments (Sunshine Act)

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.

GREGORY ZELL, O.D.'s Medicare Part D volume vs every U.S. prescriber

Total Medicare Part D claims, 2023 — across all CMS prescribers nationally

15 0th percentile higher than 0% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). This entry sits in this band. 200–400: 182,923 prescribers (13%). Above this entry. 400–600: 90,619 prescribers (7%). Above this entry. 600–800: 56,224 prescribers (4%). Above this entry. 800–1,000: 40,919 prescribers (3%). Above this entry. 1,000–1,200: 31,827 prescribers (2%). Above this entry. 1,200–1,400: 26,224 prescribers (2%). Above this entry. 1,400–1,600: 21,710 prescribers (2%). Above this entry. 1,600–1,800: 19,072 prescribers (1%). Above this entry. 1,800–2,000: 16,451 prescribers (1%). Above this entry. 2,000–2,200: 213,991 prescribers (16%). Above this entry. This provider 0 2K+ every Part D prescriber (claims/yr), bucketed by value

Each bar is a band; taller bars hold more prescribers. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.

Source CMS Medicare Part D Prescriber Public Use File · 2023

What does the federal data show about GREGORY ZELL, O.D.?

Quality data not reported

NPI registry status

Active

Issued 03/29/2006

NPI 1679534705

Primary specialty

Corneal and Contact Management Optometrist

Niche

1,549 US NPIs in this specialty

Medicare Part D claims

15 94% vs specialty avg

2023 prescription claims

Specialty avg: 235

Specialty distribution in Montana

How Corneal and Contact Management Optometrist compares to other specialties among Montana providers

Montana providers

Corneal and Contact Management Optometrist share within Montana

1. Corneal and Contact Management Optometrist42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Corneal and Contact Management Optometrist share within Montana

Specialty board-certification context

Estimated specialty board-certified rate — Corneal and Contact Management Optometrist (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Corneal and Contact Management Optometrist ABMS/AOA estimate

Est. board-certified rate (Corneal and Contact Management Optometrist) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Corneal and Contact Management Optometrist) — 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 ZELL, O.D. appears in the CMS NPPES registry as a Corneal and Contact Management Optometrist provider holding O.D. credentials at 2510 S RESERVE ST, MISSOULA, MT, 59801, with a listed phone of (406) 721-4646. NPI 1679534705 was issued on 03/29/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what ZELL 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 15 prescription claims written by this provider, covering N/A Medicare beneficiaries and totaling roughly $445 in drug spend, split 73% brand-name and 27% 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.

Corneal and Contact Management Optometrist is a narrow specialty nationwide, with 1,549 enrolled providers across 52 states and an average of 235 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

2510 S RESERVE ST
MISSOULA, MT 59801

Provider Details

NPI 1679534705
Specialty Corneal and Contact Management Optometrist
Credentials O.D.
Gender Male
NPI Issued 03/29/2006

Hospital and facility affiliations

Facilities where GREGORY ZELL, O.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.

SHOPTIKAL LLC
MISSOULA, MT

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 ZELL, O.D.. Source: openpaymentsdata.cms.gov.

Total received

$100

Largest payer

Bausch & Lomb Americas Inc.

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 ZELL, O.D. — brand share 73.0%
Specialty average (est.)

73% brand-name claims vs 27% generic, on 15 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.

15
Total Claims
$445
Total Drug Cost
N/A
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
21
Total Day Supply
483
Brand vs Generic
73% brand / 27% generic
Brand Drug Cost
$386

Patient Demographics

Average Patient Age
74.2 years
Avg HCC Risk Score
1.61

Corneal and Contact Management Optometrist Overview

How GREGORY ZELL, O.D. fits within the Corneal and Contact Management Optometrist landscape nationally.

1,549
Corneal and Contact Management Optometrist Providers in US
52
States with Corneal and Contact Management Optometrist
235
Avg Claims per Provider

GREGORY ZELL, O.D.'s 15 claims are below the specialty average of 235.

Nearby Corneal and Contact Management Optometrist Providers in Montana

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

Compare Corneal and Contact Management Optometrist nationally: see state-by-state distribution →

Frequently Asked Questions

What is GREGORY ZELL, O.D.'s specialty?
GREGORY ZELL, O.D. specializes in Corneal and Contact Management Optometrist and practices in MISSOULA, Montana. Credentials: O.D..
How much does GREGORY ZELL, O.D. prescribe under Medicare Part D?
In 2023, GREGORY ZELL, O.D. wrote 15 Medicare Part D claims totaling $445 in drug costs for N/A beneficiaries.
Where is GREGORY ZELL, O.D. located?
GREGORY ZELL, O.D. is located at 2510 S RESERVE ST, MISSOULA, MT, 59801. Phone: (406) 721-4646.
What is GREGORY ZELL, O.D.'s NPI number?
GREGORY ZELL, O.D.'s National Provider Identifier (NPI) is 1679534705, issued on 03/29/2006.
Does GREGORY ZELL, O.D. prescribe more brand-name or generic drugs?
GREGORY ZELL, O.D.'s prescribing is 73% brand-name and 27% generic drugs by claim count, with $386 in brand drug costs.
How many Corneal and Contact Management Optometrist providers are there in the US?
There are 1,549 Corneal and Contact Management Optometrist providers across 52 states in the US. The average Corneal and Contact Management Optometrist provider writes 235 Medicare Part D claims per year.
Does GREGORY ZELL, O.D. accept Medicare?
GREGORY ZELL, O.D. appears in CMS Medicare data with 15 Part D claims and N/A Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify GREGORY ZELL, O.D.'s credentials?
GREGORY ZELL, O.D.'s NPI is 1679534705 with credentials O.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