2026 NPPES data Specialist NPI 1952394330 MD
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JOHN ELLYN, MD

Specialist in CHARLESTON, South Carolina. CMS National Plan and Provider Enumeration System profile including specialty classification, practice address, and Medicare prescribing data when reported.

Federal data — no proprietary rating. PlainDoctor publishes the actual CMS NPPES and Medicare records — NPI registration, specialty, practice location, and prescribing data — without a composite score or editorial opinion on top. Every field traces to a federal source.
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
What the federal data reveals: JOHN ELLYN, MD is a Specialist ([object Object]) practicing in CHARLESTON, South Carolina with a Medicare Part D prescribing footprint of 826 claims across 193 beneficiaries — 29% brand-name prescribing .

What stands out: JOHN ELLYN, MD filed 826 Medicare Part D claims in 2023 across CHARLESTON, South Carolina. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

JOHN ELLYN, MD at a glance

Quality data not reported

NPI registry status

Active

Issued 08/31/2005

NPI 1952394330

Primary specialty

Specialist

High-volume

69,658 US NPIs in this specialty

Medicare Part D claims

826 44% vs specialty avg

2023 prescription claims

Specialty avg: 1,474

Specialty distribution in South Carolina

How Specialist compares to other specialties among South Carolina providers

South Carolina providers

Specialist share within South Carolina

1. Specialist42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Specialist share within South Carolina

Specialty board-certification context

Estimated specialty board-certified rate — Specialist (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Specialist ABMS/AOA estimate

Est. board-certified rate (Specialist) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Specialist) — ABMS / AOA estimate

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 is a Specialist provider practicing in CHARLESTON, South Carolina, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: MD. NPI: 1952394330. This profile includes practice location, specialty classification, and organizational affiliations from the CMS provider registry. Provider information is self-reported to CMS and updated monthly.

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. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what ELLYN most recently submitted to CMS rather than a vetted directory listing, which is why patients should always confirm the practice is still at this location before scheduling.

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. These figures capture only Medicare Part D — commercial insurance, Medicaid, and cash-pay prescriptions are not included, and any drug-beneficiary cell under 11 is suppressed by CMS for patient privacy.

Specialist is a high-volume specialty nationwide, with 69,658 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

31 SMITH ST
CHARLESTON, SC 29401

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%
Specialty average (est.)

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.

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.

69,658
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.

Compare Specialist nationally: see state-by-state distribution →

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 69,658 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

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