NPI registry status
Active
2026 NPPES data Neurology Physician NPI 1821082892 MD
Verify on CMS → Michael Mark, MD
Neurology Physician in Millsboro, Delaware.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 19,866 in Neurology Physician, 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
554
Medicare Part D claims · 89 beneficiaries · Neurology Physician avg: 1K
Generic prescribing
93%
generic claims · 7% 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
Michael Mark, MD filed 554 Medicare Part D claims in 2023 as a Neurology Physician in Millsboro, Delaware, prescribing 93% generic.
- 554
- Part D claims, 2023
- 93%
- 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.
Michael Mark, MD's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
554 Top 34% higher than 66% 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
◑
Board-eligible specialty (heuristic, not verified)
Michael Mark, MD practices in an ABMS-board-eligible specialty but we don't have enough CMS-participation signals to confirm active board-certified status. Consult CertificationMatters.org (the official ABMS public lookup).
What does the federal data show about Michael Mark, MD?
Quality data not reportedPrimary specialty
Neurology Physician
Medicare Part D claims
554 58% vs specialty avg
Specialty distribution in Delaware
How Neurology Physician compares to other specialties among Delaware 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 Neurology Physician. 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).
Michael Mark, MD appears in the CMS NPPES registry as a Neurology Physician provider holding MD credentials at 28467 DUPONT BLVD, Millsboro, DE, 19966, with a listed phone of (302) 933-0111. NPI 1821082892 was issued on 09/07/2005.
Medicare Part D records for calendar year 2023 show 554 prescription claims written by this provider, covering 89 Medicare beneficiaries and totaling roughly $120K in drug spend, split 7% brand-name and 93% generic by claim count.
Neurology Physician is a mid-sized specialty nationwide, with 19,866 enrolled providers across 54 states and an average of 1,309 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 | 1821082892 |
|---|---|
| Specialty | Neurology Physician |
| Credentials | MD |
| Gender | Male |
| NPI Issued | 09/07/2005 |
Brand vs generic prescribing mix · Generic-heavy
Michael Mark, MD - brand share 7.0%
Neurology Physician average
7% brand-name claims vs 93% generic, on 554 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.
554
Total Claims
$120K
Total Drug Cost
89
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 789
- Total Day Supply
- 23,482
- Brand vs Generic
- 7% brand / 93% generic
- Brand Drug Cost
- $107K
- Generic Drug Cost
- $13K
Patient Demographics
- Average Patient Age
- 72.0 years
- Avg HCC Risk Score
- 1.15
- Gender Split
- 48% female / 52% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Michael Mark, MD prescribes most
Top Medicare Part D drugs by claim count, 2023
- Topiramate
Topiramate
72 claims
- Donepezil Hcl
Donepezil Hcl
63 claims
- Gabapentin
Gabapentin
55 claims
- Primidone
Primidone
48 claims
- Levetiracetam
Levetiracetam
32 claims
- Carbidopa-Levodopa
Carbidopa-Levodopa
31 claims
- Carbamazepine Er 26
Carbamazepine Er
26 claims
- Sertraline Hcl 26
Sertraline Hcl
26 claims
| Drug | Claims |
|---|---|
| Topiramate | 72 |
| Donepezil Hcl | 63 |
| Gabapentin | 55 |
| Primidone | 48 |
| Levetiracetam | 32 |
| Carbidopa-Levodopa Carbidopa/Levodopa | 31 |
| Carbamazepine Er Carbamazepine | 26 |
| Sertraline Hcl | 26 |
| Rivastigmine Rivastigmine Tartrate | 18 |
| Clonazepam | 16 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Neurology Physician Overview
How Michael Mark, MD fits within the Neurology Physician landscape nationally.
19,866
Neurology Physician Providers in US
54
States with Neurology Physician
1,309
Avg Claims per Provider
Michael Mark, MD's 554 claims are below the specialty average of 1,309.
Nearby Neurology Physician Providers in Delaware
Other clinicians with the same primary specialty enrolled in Delaware, drawn from the same CMS NPPES roster as Mark.
Dr. Muhammad Afzal
MD
Newark, DE
Dr. Gina Alderson
MD
Seaford, DE
Dr. Narsis Aminian
MD
Newark, DE
Dr. Enrica Arnaudo
MD
Newark, DE
Dr. Sung Bae
MD
Newark, DE
Compare Neurology Physician 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 Delaware medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Neurology Physician 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 Michael Mark, MD's specialty? ▼
Michael Mark, MD specializes in Neurology Physician and practices in Millsboro, Delaware. Credentials: MD.
How much does Michael Mark, MD prescribe under Medicare Part D? ▼
In 2023, Michael Mark, MD wrote 554 Medicare Part D claims totaling $120K in drug costs for 89 beneficiaries.
Where is Michael Mark, MD located? ▼
Michael Mark, MD is located at 28467 DUPONT BLVD, Millsboro, DE, 19966. Phone: (302) 933-0111.
What is Michael Mark, MD's NPI number? ▼
Michael Mark, MD's National Provider Identifier (NPI) is 1821082892, issued on 09/07/2005.
Does Michael Mark, MD prescribe more brand-name or generic drugs? ▼
Michael Mark, MD's prescribing is 7% brand-name and 93% generic drugs by claim count, with $107K in brand drug costs.
How many Neurology Physician providers are there in the US? ▼
There are 19,866 Neurology Physician providers across 54 states in the US. The average Neurology Physician provider writes 1,309 Medicare Part D claims per year.
What drugs does Michael Mark, MD prescribe most often? ▼
Based on 2023 Medicare Part D data, Michael Mark, MD's most frequently prescribed drugs include Topiramate, Donepezil Hcl, Gabapentin. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Michael Mark, MD accept Medicare? ▼
Michael Mark, MD appears in CMS Medicare data with 554 Part D claims and 89 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Michael Mark, MD's credentials? ▼
Michael Mark, MD's NPI is 1821082892 with credentials MD. 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.