Warren Marc Ross, M.D.
Internal Medicine Physician · Ellicott City, MD
Warren Marc Ross, M.D. is an internal medicine physician with a practice address in Ellicott City, Maryland, and NPI 1770568891, issued on Dec 12, 2005. Check the license (Maryland D0017821, as entered in NPPES) on the Maryland Board of Physicians; the Medicare figures below come from public CMS files.
- Name
- Warren Marc Ross
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- D0017821 MD
Self-reported in NPPES; status is on the state search - Practice location
- 4801 Dorsey Hall Dr, Ellicott City, MD 21042
- Phone
- (410) 997-7660
- Enumerated
- Dec 12, 2005
- Record last updated
- Dec 31, 2009 (not updated in 17 years: call before relying on the address or phone)
- Fax
- (410) 997-7665
- Medicare enrollment
- Enrolled (PECOS I20100301000329); accepts Medicare assignment
- Medical or professional school
- State University Of New York At Buffalo School Of Medicine, 1971
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 3,904 in Maryland → Look up another NPI →
Also registered at 4801 Dorsey Hall Dr
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Joseph Aleo, M.D.Internal Medicine Physician1831176577
- Joshua Anderson, MS, PA-CMedical Physician Assistant1891005484
- Richard Bacharach, MDPsychiatry Physician1306852439
- Thomas Boettger, PTPhysical Medicine & Rehabilitation Physician1447246384
- Hanbiao Cao, L.AC.Acupuncturist1518090810
- Melissa Conti, P.A.Internal Medicine Physician1194802702
Verify Warren Marc Ross in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMaryland Board of Physicians
Search for license D0017821Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
90% more Medicare Part D claims than the average internal medicine physician in 2024
6,022 Medicare Part D claims for 563 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 12% of claims. 28 claims were for opioids.
Most prescribed
- Rosuvastatin Calcium555 claims
- Amlodipine Besylate359 claims
- Atorvastatin Calcium263 claims
- Levothyroxine Sodium254 claims
- Olmesartan Medoxomil221 claims
- Telmisartan166 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.
Industry payments in 2024: $1,196.56
49 payments; by number, the most common kind was food and beverage; the largest payer was Amgen Inc. The 50,334 providers of this specialty with any payment received $1,303.06 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Bills Medicare through one group practice
- Lifebridge Medical Associates LLCEllicott City, MD
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Warren Marc Ross among 3,904 internal medicine physician records in Maryland
Warren Marc Ross, M.D. is one of 3,904 internal medicine physician records with a practice address in Maryland. 77% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2005, is newer than 0% of them.
- NPI issued2005 · 0% of these records are older, 91% newer
- In a Medicare fileYes · 77% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated1971 · median 2003 among the 2,445 with a school on file
- Record last updated2009 · 59% 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 Maryland practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
32 internal medicine physician records list a practice address in Ellicott City
They are 32 of the 1,648 NPPES records with a practice address in Ellicott City, and 3,904 internal medicine physician records in Maryland.
All 3,904 in Maryland → Every provider in Ellicott City → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Joseph Aleo, M.D.Ellicott City, MD 210421831176577
- Marie-Alberte Boursiquot, M.DEllicott City, MD 210421578571618
- Melissa Conti, P.A.Ellicott City, MD 210421194802702
- Mitul Dave, MDEllicott City, MD 210421396833604
- Ujwala Desai, MDEllicott City, MD 210421952307258
- Rupal Desai, M.D.Ellicott City, MD 210421376634626
- Steven Eversley, M.D.Ellicott City, MD 210421144205865
- Jeffrey Kaplan, M.D.Ellicott City, MD 210421275590457
Common questions
What is Warren Marc Ross, M.D.'s NPI number?
Warren Marc Ross, M.D.'s National Provider Identifier (NPI) is 1770568891, issued on Dec 12, 2005. An NPI identifies a provider in billing; it is not a license.
Where is Warren Marc Ross, M.D. located?
The NPPES record lists a practice address at 4801 Dorsey Hall Dr, Ellicott City, MD, 21042. Phone: (410) 997-7660. Providers update this record themselves, so call before visiting.
How can I verify Warren Marc Ross, M.D.'s license?
NPPES lists Maryland license number D0017821, as entered by the provider. Search the Maryland Board of Physicians at https://www.mbp.state.md.us/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Warren Marc Ross, M.D. prescribe under Medicare Part D?
In 2024, Warren Marc Ross, M.D. had 6,022 Medicare Part D claims for 563 beneficiaries; 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.