Dr. Marcus R Williams , MD
Internal Medicine β’ Exton, PA
80 W Welsh Pool Rd, Suite 101s
Exton, PA 193411233
This profile restates public CMS/NPPES data; T-MedInfo gives no medical advice — consult a licensed professional, and call 911 for emergencies.
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Dr. Marcus Williams is listed in NPPES under Internal Medicine.
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NPI assigned on October 16, 2006; this date does not establish years in practice.
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Published CMS data list 539 Medicare Part D prescriptions, including refills, in 2014.
Source: CMS, Medicare Part D Prescribers β by Provider and Drug, 2014. Published rows only; this is not a quality measure.
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Published Part D records, 2014:
- Gabapentin β 88 prescription fills, including refills.
- Oxycodone Hcl β 83 prescription fills, including refills.
- Naproxen β 53 prescription fills, including refills.
Source: CMS, Medicare Part D Prescribers β by Provider and Drug, 2014. Drug names come from pharmacy claims. Listing a drug here is not an endorsement or a recommendation.
See all 19 records in the table Β· Guide: How to read Medicare Part D prescriber data
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Medicare Part D prescriptions went from 12 in 2013 to 539 in 2014.
Source: CMS, Medicare Part D Prescribers β by Provider and Drug, 2013β2014.
Practice Location & Contact Primary Location
80 W Welsh Pool Rd
Suite 101s
Exton, PA 193411233
Matched by practice address or phone in NPPES. A shared address or phone does not confirm that this clinician works there.
What Public CMS Data Show
Internal Medicine: NPPES taxonomy is a reported classification, not proof of board certification.
30-day fills
543 standardized 30-day fills in 2014
CMS converts prescriptions to 30-day supplies so they can be compared. A 90-day prescription counts as about three 30-day fills.
What this does not show: 30-day fills
It is not a count of patients and not a measure of quality.
Part D drug cost
$23,586 in 2014
The total cost of these prescriptions in 2014, paid by Medicare drug plans, patients and other payers together.
It shows the total spending on drugs this clinician prescribed, not what any one patient paid.
What this does not show: Part D drug cost
A higher cost often reflects the type of medicines a specialty uses. It is not your out-of-pocket cost and not a measure of quality.
Source: CMS, Medicare Part D Prescribers β by Provider and Drug, 2014.
Industry payments (Open Payments)
Fewer than 11 payment records totaling $24.54 in 2025
Drug and medical device companies must report certain payments to doctors and some other clinicians to CMS, such as meals, travel, speaking fees or research funding.
It shows reported financial ties between this clinician and companies. You can ask your clinician about them.
These records are submitted by drug and medical device companies, and a reported payment does not necessarily mean the financial relationship is improper.
General: payments not tied to research, such as meals, travel, consulting or speaking fees.
A reported payment does not necessarily mean the financial relationship is improper. Research payments can go to a hospital or university for a study the clinician leads, not to the clinician personally. Clinicians can dispute records with the company that reported them.
Source: CMS Open Payments, program year 2025.
NPI first issued
2006
The year this clinician's National Provider Identifier (NPI) was issued. An NPI is a unique 10-digit ID that US health care providers use for billing.
What this does not show: NPI first issued
NPIs have been issued only since 2005, so this year is not necessarily when the clinician started practicing.
Source: CMS NPPES NPI Registry.
Medicare assignment not listed
CMS data do not show whether this clinician accepts Medicare assignment. This does not mean they do not accept Medicare. Ask the office.
Medicare assignment applies to Original Medicare. It does not tell you whether the clinician is in a Medicare Advantage plan's network, accepts other insurance, or is taking new patients.
Source: CMS Doctors and Clinicians; Medicare.gov, βDoes your provider accept Medicare as full payment?β
No telehealth indicator
CMS shows this indicator only when recent Medicare claims include telehealth services. The clinician may still offer telehealth; ask the office.
Source: CMS, Telehealth Indicator on Medicare Care Compare (fact sheet, January 2023); CMS Doctors and Clinicians.
Compared with the same specialty in Exton and Pennsylvania
Billing and prescribing volume is not a quality rating.
Medicare Part D
Comparisons use 2024 data. The latest CMS data for Dr. Williams are from 2014.
14 active clinicians are listed under Internal Medicine with a practice address in Exton, PA (7,304 in Pennsylvania).
Addresses are self-reported to NPPES and may be out of date.
Telehealth indicator in Exton
14.3% of these 14 clinicians have the CMS telehealth indicator.
35.7% of these 14 clinicians are listed by CMS as accepting Medicare assignment.
CMS data by year
Changes may reflect reporting, coverage or privacy limits, not changes in care quality.
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Medicare Part D prescriptions
Medicare Part D prescriptions went from 12 in 2013 to 539 in 2014.
- 2013: 12
- 2014: 539
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30-day fills
30-day fills went from 12 in 2013 to 543 in 2014.
- 2013: 12
- 2014: 543
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Part D drug cost
Part D drug cost went from $419 in 2013 to $23,586 in 2014.
- 2013: $419
- 2014: $23,586
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Industry payments (Open Payments)
CMS data for industry payments (Open Payments) are available for 2025 only.
Sources: CMS Medicare Part D Prescribers (2014), CMS Open Payments (2025), CMS Doctors and Clinicians, CMS NPPES NPI Registry. Specialty names follow the NUCC Health Care Provider Taxonomy.
Text: T-MedInfo Β· Report an error.
Pharma & Medical Device Financial Disclosures
Payments and other transfers of value that drug and medical device companies reported to CMS Open Payments
Program year 2025 (payments made January 1 β December 31, 2025): fewer than 11 records totaling $24.54.
| Manufacturer | Payment Nature | Product | Type | Amount ($) |
|---|---|---|---|---|
| Abbott Laboratories |
Food and Beverage
In-kind items and services
|
ESPRIT | General | $24.54 |
Source: CMS Open Payments, program year 2025, released June 30, 2026.
Medicare Part D Prescribing Profile & Medications
Medicare Part D prescriptions filled, including refills, in 2014.
| Brand Name | Generic Name | Prescriptions | Day Supply | Total Cost | Patients |
|---|---|---|---|---|---|
| Gabapentin | Gabapentin | 88 | 2,027 | $1,905.86 | 58 |
| Oxycodone Hcl | Oxycodone Hcl | 83 | 1,701 | $3,859.86 | 58 |
| Naproxen | Naproxen | 53 | 1,037 | $278.83 | 44 |
| Oxycodone-Acetaminophen | Oxycodone Hcl/Acetaminophen | 48 | 805 | $1,989.63 | 37 |
| Tramadol Hcl | Tramadol Hcl | 26 | 589 | $140.53 | 18 |
| Diclofenac Sodium | Diclofenac Sodium | 25 | 595 | $362.80 | 21 |
| Topiramate | Topiramate | 22 | 635 | $136.24 | β |
| Morphine Sulfate Er | Morphine Sulfate | 22 | 494 | $1,224.68 | 11 |
| Endocet | Oxycodone Hcl/Acetaminophen | 20 | 404 | $1,311.25 | 14 |
| Suboxone | Buprenorphine Hcl/Naloxone Hcl | 20 | 380 | $8,502.75 | β |
| Methadone Hcl | Methadone Hcl | 18 | 365 | $142.39 | 12 |
| Omeprazole | Omeprazole | 17 | 366 | $127.75 | 12 |
| Cyclobenzaprine Hcl | Cyclobenzaprine Hcl | 16 | 282 | $147.12 | 14 |
| Trazodone Hcl | Trazodone Hcl | 16 | 480 | $113.95 | β |
| Metoprolol Tartrate | Metoprolol Tartrate | 14 | 420 | $89.56 | β |
| Lisinopril | Lisinopril | 13 | 350 | $82.92 | β |
| Clonazepam | Clonazepam | 13 | 360 | $76.27 | β |
| Hydrochlorothiazide | Hydrochlorothiazide | 13 | 390 | $44.37 | β |
| Oxycontin | Oxycodone Hcl | 12 | 213 | $3,049.60 | 12 |
Source: CMS Part D by Provider and Drug, 2014; rows below 11 claims omitted by CMS; volume isn’t quality. Privacy limits
Specialties & License Numbers Reported to NPPES
NUCC Taxonomy Code: 207R00000X
A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.
Additional State Medicaid & Healthcare Payer Identifiers
Clinicians Sharing This Practice Address or Phone
Clinicians sharing this NPPES address, phone or fax; a shared contact does not mean they work together.
Optometrist
Doctor of Optometry
Allergy & Immunology
Doctor of Medicine (M.D.)
Audiologist-Hearing Aid Fitter
Master of Arts, CCCA
Audiologist
Doctor of Audiology
Career & Practice History
NPI enumerated October 16, 2006.
No changes to the name, practice address, taxonomy or NPI status in this record have been observed in the monthly NPPES data files from January 2017 to August 2026.
NPI Administrative Meta
Other Internal Medicine Providers in Exton
- Dr. Rashna Staid, MD
- Dr. Manjula Naik, MD
- Dr. Sailaja Rao, MD
- Dr. Shagufta Shaikh, MD
- Dr. Susan Kohli, MD
- Dr. Christine Meyer, MD
Mailing Address
80 W Welsh Pool Rd, Suite 101s
Exton, PA 193411233
Phone: 4844832745