NPI registry status
Active
2026 NPPES data Specialist NPI 1952394330 MD
Verify on CMS → John Ellyn, MD
Specialist in Charleston, South Carolina.
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
826
Medicare Part D claims · 193 beneficiaries · Specialist avg: 1K
Generic prescribing
71%
generic claims · 29% 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
John Ellyn, MD filed 826 Medicare Part D claims in 2023 as a Specialist in Charleston, South Carolina, prescribing 71% generic.
- 826
- Part D claims, 2023
- 71%
- 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.
John Ellyn, MD's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
826 Top 27% higher than 73% 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 John Ellyn, MD?
Quality data not reportedPrimary specialty
Specialist
Medicare Part D claims
826 44% vs specialty avg
Specialty distribution in South Carolina
How Specialist compares to other specialties among South Carolina 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).
John Ellyn, MD appears in the CMS NPPES registry as a Specialist provider holding MD credentials at 31 SMITH ST, Charleston, SC, 29401, with a listed phone of (843) 577-6506. NPI 1952394330 was issued on 08/31/2005.
Medicare Part D records for calendar year 2023 show 826 prescription claims written by this provider, covering 193 Medicare beneficiaries and totaling roughly $115K in drug spend, split 29% brand-name and 71% 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 | 1952394330 |
|---|---|
| Specialty | Specialist |
| Credentials | MD |
| Gender | Male |
| NPI Issued | 08/31/2005 |
Brand vs generic prescribing mix · Above average
John Ellyn, MD - brand share 29.0%
Specialist average
29% brand-name claims vs 71% generic, on 826 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.
826
Total Claims
$115K
Total Drug Cost
193
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 1,944
- Total Day Supply
- 57,661
- Brand vs Generic
- 29% brand / 71% generic
- Brand Drug Cost
- $99K
- Generic Drug Cost
- $16K
Patient Demographics
- Average Patient Age
- 76.9 years
- Avg HCC Risk Score
- 1.24
- Gender Split
- 62% female / 38% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What John Ellyn, MD prescribes most
Top Medicare Part D drugs by claim count, 2023
- Latanoprost
Latanoprost
384 claims
- Dorzolamide-Timolol 139
Dorzolamide-Timolol
139 claims
- Timolol Maleate 55
Timolol Maleate
55 claims
- Lumigan 51
Lumigan
51 claims
- Rocklatan 41
Rocklatan
41 claims
- Dorzolamide Hcl 32
Dorzolamide Hcl
32 claims
- Brimonidine Tartrate 29
Brimonidine Tartrate
29 claims
- Azopt 13
Azopt
13 claims
| Drug | Claims |
|---|---|
| Latanoprost | 384 |
| Dorzolamide-Timolol Dorzolamide Hcl/Timolol Maleat | 139 |
| Timolol Maleate | 55 |
| Lumigan Bimatoprost | 51 |
| Rocklatan Netarsudil Mesylat/Latanoprost | 41 |
| Dorzolamide Hcl | 32 |
| Brimonidine Tartrate | 29 |
| Azopt Brinzolamide | 13 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Specialist Overview
How John Ellyn, MD fits within the Specialist landscape nationally.
69,608
Specialist Providers in US
55
States with Specialist
1,474
Avg Claims per Provider
John Ellyn, MD's 826 claims are below the specialty average of 1,474.
Nearby Specialist Providers in South Carolina
Other clinicians with the same primary specialty enrolled in South Carolina, drawn from the same CMS NPPES roster as Ellyn.
Dr. Michael Abraham
ATC, PES
Fort Mill, SC
Dr. Joneen Adams
MS
Georgetown, SC
Dr. Michael Alday
MD
Spartanburg, SC
John Alexander
Columbia, SC
Dr. William Allen
MD
Columbia, SC
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 South Carolina 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.
Healthcare Guides
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How to Find a Doctor
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Medical Specialties Explained
Who treats what and how specialties differ
Understanding Medicare Claims Data
What prescribing data reveals about a provider
In-Network vs Out-of-Network
How insurance networks affect your costs
Telehealth Guide
Virtual care options and coverage in 2026
Explore South Carolina
Frequently Asked Questions
What is John Ellyn, MD's specialty? ▼
John Ellyn, MD specializes in Specialist and practices in Charleston, South Carolina. Credentials: MD.
How much does John Ellyn, MD prescribe under Medicare Part D? ▼
In 2023, John Ellyn, MD wrote 826 Medicare Part D claims totaling $115K in drug costs for 193 beneficiaries.
Where is John Ellyn, MD located? ▼
John Ellyn, MD is located at 31 SMITH ST, Charleston, SC, 29401. Phone: (843) 577-6506.
What is John Ellyn, MD's NPI number? ▼
John Ellyn, MD's National Provider Identifier (NPI) is 1952394330, issued on 08/31/2005.
Does John Ellyn, MD prescribe more brand-name or generic drugs? ▼
John Ellyn, MD's prescribing is 29% brand-name and 71% generic drugs by claim count, with $99K 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 John Ellyn, MD prescribe most often? ▼
Based on 2023 Medicare Part D data, John Ellyn, MD's most frequently prescribed drugs include Latanoprost, Dorzolamide-Timolol, Timolol Maleate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does John Ellyn, MD accept Medicare? ▼
John Ellyn, MD appears in CMS Medicare data with 826 Part D claims and 193 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify John Ellyn, MD's credentials? ▼
John Ellyn, MD's NPI is 1952394330 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.
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.