NPI registry status
Active
2026 NPPES data Specialist NPI 1699952465 M.D.
Verify on CMS → Darrin Friesen, M.D.
Specialist in Saint Louis, Missouri.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 69,608 in Specialist, 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
1K
Medicare Part D claims · 41 beneficiaries · Specialist avg: 1K
Generic prescribing
87%
generic claims · 13% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$710.83
39 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
Darrin Friesen, M.D. filed 1,004 Medicare Part D claims in 2023 as a Specialist in Saint Louis, Missouri, prescribing 87% generic.
- 1K
- Part D claims, 2023
- 87%
- generic prescribing
- $710.83
- 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.
Darrin Friesen, M.D.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
1,004 Top 24% higher than 76% 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 Darrin Friesen, M.D.?
Quality data not reportedPrimary specialty
Specialist
Medicare Part D claims
1,004 32% vs specialty avg
Specialty distribution in Missouri
How Specialist compares to other specialties among Missouri 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 Specialist. 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).
Darrin Friesen, M.D. appears in the CMS NPPES registry as a Specialist provider holding M.D. credentials at 1750 S BRENTWOOD BLVD, Saint Louis, MO, 63144, with a listed phone of (314) 968-2111. NPI 1699952465 was issued on 01/23/2008.
Medicare Part D records for calendar year 2023 show 1,004 prescription claims written by this provider, covering 41 Medicare beneficiaries and totaling roughly $199K in drug spend, split 13% brand-name and 87% generic by claim count.
Specialist is a high-volume specialty nationwide, with 69,608 enrolled providers across 55 states and an average of 1,474 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 | 1699952465 |
|---|---|
| Specialty | Specialist |
| Credentials | M.D. |
| Gender | Male |
| NPI Issued | 01/23/2008 |
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 Darrin Friesen, M.D.. Source: openpaymentsdata.cms.gov.
Total received
$711
Largest payer
Corium, 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 · Typical
Darrin Friesen, M.D. - brand share 13.0%
Specialist average
13% brand-name claims vs 87% generic, on 1,004 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.
1,004
Total Claims
$199K
Total Drug Cost
41
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 1,417
- Total Day Supply
- 42,256
- Brand vs Generic
- 13% brand / 87% generic
- Brand Drug Cost
- $138K
- Generic Drug Cost
- $61K
Patient Demographics
- Average Patient Age
- 44.9 years
- Avg HCC Risk Score
- 0.73
- Gender Split
- 44% female / 56% male
- Age Distribution
- <65: 30, 65-74: N/A, 75-84: N/A, 85+: 0
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Darrin Friesen, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Lamotrigine
Lamotrigine
99 claims
- Ziprasidone Hcl
Ziprasidone Hcl
66 claims
- Fluoxetine Hcl
Fluoxetine Hcl
60 claims
- Dextroamphetamine-…
Dextroamphetamine-Amphet Er
53 claims
- Trazodone Hcl
Trazodone Hcl
47 claims
- Escitalopram Oxalate
Escitalopram Oxalate
46 claims
- Sertraline Hcl
Sertraline Hcl
44 claims
- Aripiprazole 37
Aripiprazole
37 claims
| Drug | Claims |
|---|---|
| Lamotrigine | 99 |
| Ziprasidone Hcl | 66 |
| Fluoxetine Hcl | 60 |
| Dextroamphetamine-Amphet Er Dextroamphetamine/Amphetamine | 53 |
| Trazodone Hcl | 47 |
| Escitalopram Oxalate | 46 |
| Sertraline Hcl | 44 |
| Aripiprazole | 37 |
| Quetiapine Fumarate Er Quetiapine Fumarate | 32 |
| Bupropion Xl Bupropion Hcl | 31 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Specialist Overview
How Darrin Friesen, M.D. fits within the Specialist landscape nationally.
69,608
Specialist Providers in US
55
States with Specialist
1,474
Avg Claims per Provider
Darrin Friesen, M.D.'s 1,004 claims are below the specialty average of 1,474.
Nearby Specialist Providers in Missouri
Other clinicians with the same primary specialty enrolled in Missouri, drawn from the same CMS NPPES roster as Friesen.
Dr. Ibrahim Abdalla
M.D.
Springfield, MO
Dr. Duncan Abongo
OT
Brookfield, MO
Dr. Juanita Achelpohl
LMT
Troy, MO
Dr. Stephanie Adams
OTR/L
Saint Peters, MO
Dr. Antoine Adem
M.D.
Saint Louis, MO
Compare Specialist 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 Missouri medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Specialist 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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Frequently Asked Questions
What is Darrin Friesen, M.D.'s specialty? ▼
Darrin Friesen, M.D. specializes in Specialist and practices in Saint Louis, Missouri. Credentials: M.D..
How much does Darrin Friesen, M.D. prescribe under Medicare Part D? ▼
In 2023, Darrin Friesen, M.D. wrote 1,004 Medicare Part D claims totaling $199K in drug costs for 41 beneficiaries.
Where is Darrin Friesen, M.D. located? ▼
Darrin Friesen, M.D. is located at 1750 S BRENTWOOD BLVD, Saint Louis, MO, 63144. Phone: (314) 968-2111.
What is Darrin Friesen, M.D.'s NPI number? ▼
Darrin Friesen, M.D.'s National Provider Identifier (NPI) is 1699952465, issued on 01/23/2008.
Does Darrin Friesen, M.D. prescribe more brand-name or generic drugs? ▼
Darrin Friesen, M.D.'s prescribing is 13% brand-name and 87% generic drugs by claim count, with $138K in brand drug costs.
How many Specialist providers are there in the US? ▼
There are 69,608 Specialist providers across 55 states in the US. The average Specialist provider writes 1,474 Medicare Part D claims per year.
What drugs does Darrin Friesen, M.D. prescribe most often? ▼
Based on 2023 Medicare Part D data, Darrin Friesen, M.D.'s most frequently prescribed drugs include Lamotrigine, Ziprasidone Hcl, Fluoxetine Hcl. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Darrin Friesen, M.D. accept Medicare? ▼
Darrin Friesen, M.D. appears in CMS Medicare data with 1,004 Part D claims and 41 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Darrin Friesen, M.D.'s credentials? ▼
Darrin Friesen, M.D.'s NPI is 1699952465 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
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.