NPI registry status
Active
2026 NPPES data Endocrinology, Diabetes & Metabolism Physician NPI 1093840811 M.D.
Verify on CMS → Mark McClanahan, M.D.
Endocrinology, Diabetes & Metabolism Physician in Fredericksburg, Virginia.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 8,078 in Endocrinology, Diabetes & Metabolism 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
8K
Medicare Part D claims · 1K beneficiaries · Endocrinology, Diabetes & Metabolism Physician avg: 3K
Generic prescribing
48%
generic claims · 45% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$469
23 payments · CMS Open Payments (Sunshine Act)
Source: CMS Medicare Part D Prescriber Public Use File, 2024
What the federal data shows
Mark McClanahan, M.D. filed 8,143 Medicare Part D claims in 2024 as an Endocrinology, Diabetes & Metabolism Physician in Fredericksburg, Virginia, prescribing 48% generic.
- 8K
- Part D claims, 2024
- 48%
- generic prescribing
- $469
- industry payments (Sunshine Act)
- ≥97th
- pct by Part D claim volume (lower-bound band)
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.
Federal trust snapshot
What official records show about Mark McClanahan, M.D.
Federal records show an active NPI with Medicare Part D prescribing activity — verifiable registry data, not a proprietary rating.
- Verified
NPI registry status
Active listing in the CMS National Provider Identifier Registry (NPI 1093840811), first enumerated 02/22/2007.
Source: CMS NPPES
- Reported
Medicare Part D participation
Filed 8,143 Medicare Part D prescription claims in the 2023 CMS public use file — indicates active Medicare prescribing participation.
Source: CMS Part D Prescriber PUF
- Reported
Board certification signal
Practices in an ABMS-board-eligible specialty; board certification not confirmed in federal records.
- Reported
Industry payment transparency
$469 in reported industry payments (23 transfers) in 2024 under the federal Sunshine Act — disclosed transfers of value, not a quality rating.
Source: CMS Open Payments
- Not in federal data
Individual sanction lookup
PlainDoctor does not publish per-provider disciplinary determinations. Confirm current license and any individual actions through the state medical board or FSMB verification service.
Source: State medical board / FSMB
This trust snapshot summarizes only what appears in federal CMS/NPPES public records. It is not a composite score, star rating, patient review, or clinical recommendation. PlainDoctor never fabricates reviews or AggregateRating schema.
CMS NPPES provider registry desk
NPI 1093840811 · Endocrinology, Diabetes & Metabolism Physician
NPI-10 · ENUM-MID · TAX-MID · RX-MID · BOOK-THIN · PHOTO-ENUM
- NPI-10 1093840811
- ENUM-MID 2007
- TAX-MID 8K Endocrinology, Diabetes
- RX-MID 8,143
- BOOK-THIN 200 in Virginia
- PHOTO-ENUM Brian Rose, MD · 2007
Mark McClanahan, M.D.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2024, across all CMS prescribers nationally
8,143 ≥ 97th percentile 97% of 1,416,883 prescribers are in lower value bands
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.
The percentile is a conservative 100-claim band: it counts only prescribers in lower claim-volume bands. Medicare Part D claim volume is activity context, not a quality measure or recommendation. See methodology § corpus placement.
Source CMS Medicare Part D Prescriber Public Use File · 2024
◑
Board-eligible specialty (heuristic, not verified)
Mark McClanahan, M.D. 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 Mark McClanahan, M.D.?
Quality data not reportedPrimary specialty
Endocrinology, Diabetes & Metabolism Physician
Medicare Part D claims
8,143 197% vs specialty avg
Specialty distribution in Virginia
How Endocrinology, Diabetes & Metabolism Physician compares to other specialties among Virginia 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 Endocrinology, Diabetes & Metabolism 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).
Practice Address
Provider Details
| NPI | 1093840811 |
|---|---|
| Specialty | Endocrinology, Diabetes & Metabolism Physician |
| Credentials | M.D. |
| Gender | Male |
| NPI Issued | 02/22/2007 |
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 Mark McClanahan, M.D.. Source: openpaymentsdata.cms.gov.
Total received
$469
Largest payer
SANOFI-AVENTIS U.S. 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 · Above average
Mark McClanahan, M.D. - brand share 45.0%
Endocrinology, Diabetes & Metabolism Physician average
45% brand-name claims vs 48% generic, on 8,143 2024 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 2024.
8,143
Total Claims
$3.7M
Total Drug Cost
1,017
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 20,989.467
- Total Day Supply
- 625,190
- Brand vs Generic
- 45% brand / 48% generic
- Brand Drug Cost
- $3.5M
- Generic Drug Cost
- $68K
- Opioid Claims
- 20 (0.2% rate)
Patient Demographics
- Average Patient Age
- 75.3 years
- Avg HCC Risk Score
- 1.35
- Gender Split
- 63% female / 37% male
- Age Distribution
- <65: 32, 65-74: 436, 75-84: 452, 85+: 97
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2024. Based on Medicare Part D data only.
What Mark McClanahan, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2024
- Levothyroxine Sodium
Levothyroxine Sodium
726 claims
- Glimepiride
Glimepiride
500 claims
- Metformin Hcl Er
Metformin Hcl Er
499 claims
- Ozempic
Ozempic
479 claims
- Synthroid
Synthroid
411 claims
- Metformin Hcl
Metformin Hcl
323 claims
- Nano 2nd Gen Pen N… 233
Nano 2nd Gen Pen Needle
233 claims
- Atorvastatin Calcium 221
Atorvastatin Calcium
221 claims
| Drug | Claims |
|---|---|
| Levothyroxine Sodium | 726 |
| Glimepiride | 500 |
| Metformin Hcl Er Metformin Hcl | 499 |
| Ozempic Semaglutide | 479 |
| Synthroid Levothyroxine Sodium | 411 |
| Metformin Hcl | 323 |
| Nano 2nd Gen Pen Needle Pen Needle, Diabetic | 233 |
| Atorvastatin Calcium | 221 |
| Jardiance Empagliflozin | 198 |
| Tresiba Flextouch U-100 Insulin Degludec | 178 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
More Endocrinology, Diabetes & Metabolism Physician in VA →
All providers in Virginia →
Compare specialties →
Endocrinology, Diabetes & Metabolism Physician Overview
How Mark McClanahan, M.D. fits within the Endocrinology, Diabetes & Metabolism Physician landscape nationally.
8,078
Endocrinology, Diabetes & Metabolism Physician Providers in US
54
States with Endocrinology, Diabetes & Metabolism Physician
2,739
Avg Claims per Provider
Mark McClanahan, M.D.'s 8,143 claims are above the specialty average of 2,739.
Nationwide Endocrinology, Diabetes & Metabolism Physician peers with similar MIPS or enrollment year
Two federal-record peer sets for McClanahan, both outside Virginia so the neighborhoods are not geographic containment.
Same NPPES enumeration year (2007)
Same-specialty clinicians who entered the NPI registry in the same calendar year, outside this state.
Nearby Endocrinology, Diabetes & Metabolism Physician Providers in Virginia
Other clinicians with the same primary specialty enrolled in Virginia, drawn from the same CMS NPPES roster as McClanahan.
One of 200 Endocrinology, Diabetes & Metabolism Physician providers enrolled in Virginia, 5 are shown here.
Dr. Mustapha Abdul-Rahman
MD
Winchester, VA
Dr. Robert Adler
M.D.
Richmond, VA
Dr. Samina Afreen
MD
Charlottesville, VA
Dr. Miriam Ahmad
M.D.
Falls Church, VA
Ahmed Al Dabbagh
MBCHB
Suffolk, VA
Compare Endocrinology, Diabetes & Metabolism Physician nationally: see state-by-state distribution →
Frequently Asked Questions
What is Mark McClanahan, M.D.'s specialty? ▼
Mark McClanahan, M.D. specializes in Endocrinology, Diabetes & Metabolism Physician and practices in Fredericksburg, Virginia. Credentials: M.D..
How much does Mark McClanahan, M.D. prescribe under Medicare Part D? ▼
In 2024, Mark McClanahan, M.D. wrote 8,143 Medicare Part D claims totaling $3.7M in drug costs for 1,017 beneficiaries.
Where is Mark McClanahan, M.D. located? ▼
Mark McClanahan, M.D. is located at 10711 SPOTSYLVANIA AVE, Fredericksburg, VA, 22408. Phone: (540) 891-8499.
What is Mark McClanahan, M.D.'s NPI number? ▼
Mark McClanahan, M.D.'s National Provider Identifier (NPI) is 1093840811, issued on 02/22/2007.
Does Mark McClanahan, M.D. prescribe more brand-name or generic drugs? ▼
Mark McClanahan, M.D.'s prescribing is 45% brand-name and 48% generic drugs by claim count, with $3.5M in brand drug costs.
Does Mark McClanahan, M.D. prescribe opioids? ▼
Yes, Mark McClanahan, M.D. had 20 opioid claims in 2024 with an opioid prescribing rate of 0.2%.
How many Endocrinology, Diabetes & Metabolism Physician providers are there in the US? ▼
There are 8,078 Endocrinology, Diabetes & Metabolism Physician providers across 54 states in the US. The average Endocrinology, Diabetes & Metabolism Physician provider writes 2,739 Medicare Part D claims per year.
What drugs does Mark McClanahan, M.D. prescribe most often? ▼
Based on 2024 Medicare Part D data, Mark McClanahan, M.D.'s most frequently prescribed drugs include Levothyroxine Sodium, Glimepiride, Metformin Hcl Er. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Mark McClanahan, M.D. accept Medicare? ▼
Mark McClanahan, M.D. appears in CMS Medicare data with 8,143 Part D claims and 1,017 Medicare beneficiaries in 2024. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Mark McClanahan, M.D.'s credentials? ▼
Mark McClanahan, M.D.'s NPI is 1093840811 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 (2024). 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 August 2026 (NPPES) / 2024 (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
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 August 2026.