NPI registry status
Active
2026 NPPES data Optometrist NPI 1669485801 OD
Verify on CMS → Gregory Kalkofen, OD
Optometrist in Clinton Twp, Michigan.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 60,484 in Optometrist, and covers specialty classification, practice address, and Medicare Part D prescribing data when reported. According to CMS, every field reflects the provider's official federal registration, see our methodology.
Federal data, no proprietary rating.
We show these CMS records as-is - no composite score, no star rating, no editorial opinion layered on top.
Prescribing volume
254
Medicare Part D claims · 96 beneficiaries · Optometrist avg: 257
Generic prescribing
60%
generic claims · 40% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$77.82
5 payments · CMS Open Payments (Sunshine Act)
Source: CMS Medicare Part D Prescriber Public Use File, 2023
Compiled from official public sources by the PlainDoctor editorial team.
What the federal data shows
Gregory Kalkofen, OD filed 254 Medicare Part D claims in 2023 as a Optometrist in Clinton Twp, Michigan, prescribing 60% generic.
- 254
- Part D claims, 2023
- 60%
- generic prescribing
- $77.82
- 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 Kalkofen, OD's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
254 49th percentile higher than 49% of 1,370,886 prescribers
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 Kalkofen, OD?
Quality data not reportedPrimary specialty
Optometrist
Medicare Part D claims
254 1% vs specialty avg
Specialty distribution in Michigan
How Optometrist compares to other specialties among Michigan providers
Board certification
Not published by CMS
CMS does not publish a per-provider board-certification field in NPPES. PlainDoctor does not have a reliable per-specialty certification rate to show for Optometrist. Verify directly:
How MIPS and board certification work
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 Kalkofen, OD appears in the CMS NPPES registry as an Optometrist provider holding OD credentials at 42550 GARFIELD, Clinton Twp, MI, 48038, with a listed phone of (586) 263-9708. NPI 1669485801 was issued on 08/15/2006.
Medicare Part D records for calendar year 2023 show 254 prescription claims written by this provider, covering 96 Medicare beneficiaries and totaling roughly $29K in drug spend, split 40% brand-name and 60% generic by claim count.
Optometrist is a high-volume specialty nationwide, with 60,484 enrolled providers across 56 states and an average of 257 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
Provider Details
| NPI | 1669485801 |
|---|---|
| Specialty | Optometrist |
| Credentials | OD |
| Gender | Male |
| NPI Issued | 08/15/2006 |
Hospital and facility affiliations
Facilities where Gregory Kalkofen, OD 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.
Optometry PC
Clinton Township, MI
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 Kalkofen, OD. Source: openpaymentsdata.cms.gov.
Total received
$78
Largest payer
CooperVision 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.
License & disciplinary context - Michigan MI-BOM 2023 annual report
Aggregate state board data only, NOT a determination of any individual provider's status. The figures below describe statewide disciplinary activity across all ~41K Michigan medical licensees in 2023 - they are NOT specific to Gregory Kalkofen, OD. To verify Gregory Kalkofen, OD's current license status, search the MI-BOM public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.
123
Total board actions, Michigan 2023
Across 120 cases
3.00
Actions per 1,000 licensees
Michigan statewide rate
probation
Most common action type
44 cases
MI-BOM publishes annual disciplinary statistics as part of public-record reporting under each state's Administrative Procedure Act. See the full breakdown by action type and year on the Michigan disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.
Brand vs generic prescribing mix · Above average
Gregory Kalkofen, OD - brand share 40.0%
Optometrist average
40% brand-name claims vs 60% generic, on 254 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.
254
Total Claims
$29K
Total Drug Cost
96
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 403
- Total Day Supply
- 10,761
- Brand vs Generic
- 40% brand / 60% generic
- Brand Drug Cost
- $20K
- Generic Drug Cost
- $9K
- Antibiotic Claims
- 13
Patient Demographics
- Average Patient Age
- 76.1 years
- Avg HCC Risk Score
- 1.05
- Gender Split
- 71% female / 29% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Gregory Kalkofen, OD prescribes most
Top Medicare Part D drugs by claim count, 2023
- Latanoprost
Latanoprost
120 claims
- Prednisolone Acetate 32
Prednisolone Acetate
32 claims
- Timolol Maleate 22
Timolol Maleate
22 claims
- Neomycin-Polymyxin… 11
Neomycin-Polymyxin-Dexameth
11 claims
| Drug | Claims |
|---|---|
| Latanoprost | 120 |
| Prednisolone Acetate | 32 |
| Timolol Maleate | 22 |
| Neomycin-Polymyxin-Dexameth Neomycin/Polymyxin B/Dexametha | 11 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Optometrist Overview
How Gregory Kalkofen, OD fits within the Optometrist landscape nationally.
60,484
Optometrist Providers in US
56
States with Optometrist
257
Avg Claims per Provider
Gregory Kalkofen, OD's 254 claims are below the specialty average of 257.
Nearby Optometrist Providers in Michigan
Other clinicians with the same primary specialty enrolled in Michigan, drawn from the same CMS NPPES roster as Kalkofen.
Dr. Brooke Abbaya
OD
Troy, MI
Dr. Richard Abbott
O.D.
Traverse City, MI
Dr. John Abdella
O.D.
Flint, MI
Hussein Abdulameer
Ann Arbor, MI
Shaina Abraham
Ann Arbor, MI
Compare Optometrist nationally: see state-by-state distribution →
Before you book an appointment
Use this federal record as your verification checklist, not as a recommendation.
- Confirm the NPI record is current in the official CMS registry, providers update their own NPPES details, and moves can lag. Verify this NPI
- Check the active license and any disciplinary history with the Michigan medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Optometrist peer on Medicare volume and prescribing patterns. Compare providers
Medicare Part D and MIPS figures describe practice patterns in federal programs only, they are not quality ratings, and PlainDoctor does not rate, rank, or recommend providers.
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Medical Specialties Explained
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Frequently Asked Questions
What is Gregory Kalkofen, OD's specialty? ▼
Gregory Kalkofen, OD specializes in Optometrist and practices in Clinton Twp, Michigan. Credentials: OD.
How much does Gregory Kalkofen, OD prescribe under Medicare Part D? ▼
In 2023, Gregory Kalkofen, OD wrote 254 Medicare Part D claims totaling $29K in drug costs for 96 beneficiaries.
Where is Gregory Kalkofen, OD located? ▼
Gregory Kalkofen, OD is located at 42550 GARFIELD, Clinton Twp, MI, 48038. Phone: (586) 263-9708.
What is Gregory Kalkofen, OD's NPI number? ▼
Gregory Kalkofen, OD's National Provider Identifier (NPI) is 1669485801, issued on 08/15/2006.
Does Gregory Kalkofen, OD prescribe more brand-name or generic drugs? ▼
Gregory Kalkofen, OD's prescribing is 40% brand-name and 60% generic drugs by claim count, with $20K in brand drug costs.
How many Optometrist providers are there in the US? ▼
There are 60,484 Optometrist providers across 56 states in the US. The average Optometrist provider writes 257 Medicare Part D claims per year.
What drugs does Gregory Kalkofen, OD prescribe most often? ▼
Based on 2023 Medicare Part D data, Gregory Kalkofen, OD's most frequently prescribed drugs include Latanoprost, Prednisolone Acetate, Timolol Maleate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Gregory Kalkofen, OD accept Medicare? ▼
Gregory Kalkofen, OD appears in CMS Medicare data with 254 Part D claims and 96 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Gregory Kalkofen, OD's credentials? ▼
Gregory Kalkofen, OD's NPI is 1669485801 with credentials OD. 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
View source datasets and methodology notes
- 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
Compiled from official public sources by the PlainDoctor editorial team.
Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of May 2026.