NPI registry status
Active
2026 NPPES data Optometrist NPI 1417954553 O.D.
Verify on CMS → Darwin Dalen, O.D.
Optometrist in Grand Rapids, Minnesota.
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
200
Medicare Part D claims · 55 beneficiaries · Optometrist avg: 257
Generic prescribing
66%
generic claims · 34% brand-name · higher generic rates reduce patient out-of-pocket costs
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
Darwin Dalen, O.D. filed 200 Medicare Part D claims in 2023 as a Optometrist in Grand Rapids, Minnesota, prescribing 66% generic.
- 200
- Part D claims, 2023
- 66%
- generic prescribing
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.
Darwin Dalen, O.D.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
200 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 Darwin Dalen, O.D.?
Quality data not reportedPrimary specialty
Optometrist
Medicare Part D claims
200 22% vs specialty avg
Specialty distribution in Minnesota
How Optometrist compares to other specialties among Minnesota 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).
Darwin Dalen, O.D. appears in the CMS NPPES registry as an Optometrist provider holding O.D. credentials at 201 NW 4TH ST, Grand Rapids, MN, 55744, with a listed phone of (218) 326-9619. NPI 1417954553 was issued on 07/05/2005.
Medicare Part D records for calendar year 2023 show 200 prescription claims written by this provider, covering 55 Medicare beneficiaries and totaling roughly $12K in drug spend, split 34% brand-name and 66% 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 | 1417954553 |
|---|---|
| Specialty | Optometrist |
| Credentials | O.D. |
| Gender | Male |
| NPI Issued | 07/05/2005 |
Brand vs generic prescribing mix · Above average
Darwin Dalen, O.D. - brand share 34.0%
Optometrist average
34% brand-name claims vs 66% generic, on 200 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.
200
Total Claims
$12K
Total Drug Cost
55
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 445
- Total Day Supply
- 12,945
- Brand vs Generic
- 34% brand / 66% generic
- Brand Drug Cost
- $6K
- Generic Drug Cost
- $6K
Patient Demographics
- Average Patient Age
- 75.2 years
- Avg HCC Risk Score
- 0.85
- Gender Split
- 67% female / 33% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Darwin Dalen, O.D. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Latanoprost
Latanoprost
121 claims
- Dorzolamide Hcl 21
Dorzolamide Hcl
21 claims
- Timolol Maleate 14
Timolol Maleate
14 claims
| Drug | Claims |
|---|---|
| Latanoprost | 121 |
| Dorzolamide Hcl | 21 |
| Timolol Maleate | 14 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Optometrist Overview
How Darwin Dalen, O.D. fits within the Optometrist landscape nationally.
60,484
Optometrist Providers in US
56
States with Optometrist
257
Avg Claims per Provider
Darwin Dalen, O.D.'s 200 claims are below the specialty average of 257.
Nearby Optometrist Providers in Minnesota
Other clinicians with the same primary specialty enrolled in Minnesota, drawn from the same CMS NPPES roster as Dalen.
Dr. Michael Ackermann
OD
Lake City, MN
Dr. Bradley Adams
O.D.
Brainerd, MN
Dr. Kristin Adams
OD
Minneapolis, MN
Dr. Anna Aho
OD
Annandale, MN
Dr. Kamran Ahrar
OD
Lakeville, MN
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 Minnesota 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.
Healthcare Guides
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Medical Specialties Explained
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Understanding Medicare Claims Data
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Frequently Asked Questions
What is Darwin Dalen, O.D.'s specialty? ▼
Darwin Dalen, O.D. specializes in Optometrist and practices in Grand Rapids, Minnesota. Credentials: O.D..
How much does Darwin Dalen, O.D. prescribe under Medicare Part D? ▼
In 2023, Darwin Dalen, O.D. wrote 200 Medicare Part D claims totaling $12K in drug costs for 55 beneficiaries.
Where is Darwin Dalen, O.D. located? ▼
Darwin Dalen, O.D. is located at 201 NW 4TH ST, Grand Rapids, MN, 55744. Phone: (218) 326-9619.
What is Darwin Dalen, O.D.'s NPI number? ▼
Darwin Dalen, O.D.'s National Provider Identifier (NPI) is 1417954553, issued on 07/05/2005.
Does Darwin Dalen, O.D. prescribe more brand-name or generic drugs? ▼
Darwin Dalen, O.D.'s prescribing is 34% brand-name and 66% generic drugs by claim count, with $6K 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 Darwin Dalen, O.D. prescribe most often? ▼
Based on 2023 Medicare Part D data, Darwin Dalen, O.D.'s most frequently prescribed drugs include Latanoprost, Dorzolamide Hcl, Timolol Maleate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Darwin Dalen, O.D. accept Medicare? ▼
Darwin Dalen, O.D. appears in CMS Medicare data with 200 Part D claims and 55 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Darwin Dalen, O.D.'s credentials? ▼
Darwin Dalen, O.D.'s NPI is 1417954553 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
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.