William Demarco, DO
Internal Medicine Physician · Great Barrington, MA
William Demarco, DO is an internal medicine physician with a practice address in Great Barrington, Massachusetts, and NPI 1124103577, issued on Oct 26, 2006. Check the license (Massachusetts 59492, as entered in NPPES) on the Massachusetts Board of Registration in Medicine; the Medicare figures below come from public CMS files.
- Name
- William Demarco
- Credential
- DO
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- 59492 MA
Self-reported in NPPES; status is on the state search - Practice location
- 29 Lewis Ave, Great Barrington, MA 01230
- Phone
- (413) 496-6820
- Enumerated
- Oct 26, 2006
- Record last updated
- Jan 24, 2008 (not updated in 18 years: call before relying on the address or phone)
- Fax
- (413) 496-6821
- Medicaid ID
- 3045161 MA
- Medicare enrollment
- Enrolled (PECOS I20040611001446); accepts Medicare assignment
- Medical or professional school
- University Of New England, College Of Osteo Medicine, 1984
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 6,825 in Massachusetts → Look up another NPI →
Also registered at 29 Lewis Ave
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Gayle Armstrong, NPFamily Nurse Practitioner1235279597
- Laurie BasinaitAdult Medicine Physician1326442203
- Brian BurkeInternal Medicine Physician1376672519
- Rahul Chandra Shekhar, M.D.Hospitalist Physician1386085165
- Michael Codini, MDEmergency Medicine Physician1093101313
Verify William Demarco in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMassachusetts Board of Registration in Medicine
Search for license 59492Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Most of these Medicare Part D claims are vaccines, 100% of the cost of the top drugs
12 Medicare Part D claims, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 100% of claims.
Most prescribed
Pharmacies often give vaccines under a standing order that names one clinician, and CMS counts every such claim under that clinician's NPI. These claims are therefore not a measure of this clinician's own prescribing.
- Shingrix12 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Bills Medicare through one group practice
- Berkshire Medical Center IncPittsfield, MA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
William Demarco among 6,825 internal medicine physician records in Massachusetts
William Demarco, DO is one of 6,825 internal medicine physician records with a practice address in Massachusetts. 75% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 12% of them.
- NPI issued2006 · 12% of these records are older, 54% newer
- In a Medicare fileYes · 75% of these records are
- In the CMS Doctors and Clinicians fileYes · 60% of these records are
- Graduated1984 · median 2004 among the 4,103 with a school on file
- Record last updated2008 · 64% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207R00000X and a Massachusetts practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
7 internal medicine physician records list a practice address in Great Barrington
They are 7 of the 278 NPPES records with a practice address in Great Barrington, and 6,825 internal medicine physician records in Massachusetts.
All 6,825 in Massachusetts → Every provider in Great Barrington → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Brian BurkeGreat Barrington, MA 012301376672519
- Eric Bush, MDGt Barrington, MA 012301801987151
- Katrina Curtiss, NPGreat Barrington, MA 012301821882770
- John Dubois, M.D.Gt Barrington, MA 012301861642563
- Mani George, MDGt Barrington, MA 012301497843650
- Alan Inglis, MDGreat Barrington, MA 012301801840889
- Daniel Patel, MDGt Barrington, MA 012301588755011
- Andrew Potler, DOGt Barrington, MA 012301427149798
Common questions
What is William Demarco, DO's NPI number?
William Demarco, DO's National Provider Identifier (NPI) is 1124103577, issued on Oct 26, 2006. An NPI identifies a provider in billing; it is not a license.
Where is William Demarco, DO located?
The NPPES record lists a practice address at 29 Lewis Ave, Great Barrington, MA, 01230. Phone: (413) 496-6820. Providers update this record themselves, so call before visiting.
How can I verify William Demarco, DO's license?
NPPES lists Massachusetts license number 59492, as entered by the provider. Search the Massachusetts Board of Registration in Medicine at https://findmydoctor.mass.gov/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does William Demarco, DO prescribe under Medicare Part D?
In 2024, William Demarco, DO had 12 Medicare Part D claims; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.