James Stewart Lang, M.D.
Internal Medicine Physician · Chelsea, MA
James Stewart Lang, M.D. is an internal medicine physician with a practice address in Chelsea, Massachusetts, and NPI 1528488798, issued on Apr 25, 2014. Check the license (Massachusetts 269504, as entered in NPPES) on the Massachusetts Board of Registration in Medicine; the Medicare figures below come from public CMS files.
- Name
- James Stewart Lang
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License numbers
- 269504 MA
MD61493634 WA
Self-reported in NPPES; status is on the state search - Practice location
- 151 Everett Ave, Chelsea, MA 02150
- Phone
- (617) 889-8520
- Enumerated
- Apr 25, 2014
- Record last updated
- Oct 15, 2025
- Fax
- (617) 889-8571
- Medicare enrollment
- Enrolled (PECOS I20240306002367); accepts Medicare assignment
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 6,825 in Massachusetts → Look up another NPI →
Also registered at 151 Everett Ave
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify James Stewart Lang in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMassachusetts Board of Registration in Medicine
Search for license 269504Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
48% fewer Medicare Part D claims than the average internal medicine physician in 2024
1,644 Medicare Part D claims for 268 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. 23 claims were for opioids.
Most prescribed
- Atorvastatin Calcium185 claims
- Amlodipine Besylate74 claims
- Losartan Potassium67 claims
- Lisinopril65 claims
- Omeprazole57 claims
- Levothyroxine Sodium55 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 2 group practices
- Optum Care Washington PLLCEverett, WA
- The General Hospital CorporationBoston, MA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
James Stewart Lang among 6,825 internal medicine physician records in Massachusetts
James Stewart Lang, M.D. 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 2014, is newer than 72% of them.
- NPI issued2014 · 72% of these records are older, 26% newer
- In a Medicare fileYes · 75% of these records are
- In the CMS Doctors and Clinicians fileYes · 60% of these records are
- Graduated2014 · median 2004 among the 4,103 with a school on file
- Record last updated2025 · 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).
36 internal medicine physician records list a practice address in Chelsea
They are 36 of the 998 NPPES records with a practice address in Chelsea, and 6,825 internal medicine physician records in Massachusetts.
All 6,825 in Massachusetts → Every provider in Chelsea → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Sefik Abdulhayoglu, MDChelsea, MA 021501659358166
- Jose Abrego, MDChelsea, MA 021501205808722
- Nancy Adams, M.D.Chelsea, MA 021501649236365
- Wynne Armand, MDChelsea, MA 021501497745939
- Judith Fisch, MDChelsea, MA 021501487644126
- Herman Gomez, MDChelsea, MA 021501639153414
- Ann Kao, MDChelsea, MA 021501588643282
- Cindy Levine, M.D.Chelsea, MA 021501437137270
Common questions
What is James Stewart Lang, M.D.'s NPI number?
James Stewart Lang, M.D.'s National Provider Identifier (NPI) is 1528488798, issued on Apr 25, 2014. An NPI identifies a provider in billing; it is not a license.
Where is James Stewart Lang, M.D. located?
The NPPES record lists a practice address at 151 Everett Ave, Chelsea, MA, 02150. Phone: (617) 889-8520. Providers update this record themselves, so call before visiting.
How can I verify James Stewart Lang, M.D.'s license?
NPPES lists Massachusetts license number 269504, 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 James Stewart Lang, M.D. prescribe under Medicare Part D?
In 2024, James Stewart Lang, M.D. had 1,644 Medicare Part D claims for 268 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.