Janet C. Larson, M.D.
Internal Medicine Physician · Boston, MA
Janet C. Larson, M.D. is an internal medicine physician with a practice address in Boston, Massachusetts, and NPI 1831159326, issued on Mar 27, 2006. Check the license (Massachusetts 220603, as entered in NPPES) on the Massachusetts Board of Registration in Medicine; the federal record below is the public data PlainDoctor holds for this provider.
- Name
- Janet C. Larson
- Credential
- M.D.
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- 220603 MA
Self-reported in NPPES; status is on the state search - Practice location
- 801 Massachusetts Ave, Boston, MA 02118
- Phone
- (617) 414-7399
- Enumerated
- Mar 27, 2006
- Record last updated
- Apr 3, 2024
- Fax
- (617) 414-4676
- Medicare enrollment
- Enrolled (PECOS I20260507000896); accepts Medicare assignment
- Medical or professional school
- Boston University School Of Medicine, 1998
- Entity
- Type 1 · individual
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- Peter ArdenStudent in an Organized Health Care Education/Training Program1821892795
- Nabila Azad, M.D.Internal Medicine Physician1881073138
Verify Janet C. Larson in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMassachusetts Board of Registration in Medicine
Search for license 220603Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Janet C. Larson among 6,825 internal medicine physician records in Massachusetts
Janet C. Larson, 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 not. Its NPI, issued in 2006, is newer than 12% of them.
- NPI issued2006 · 12% of these records are older, 54% newer
- In a Medicare fileNo · 75% of these records are
- In the CMS Doctors and Clinicians fileYes · 60% of these records are
- Graduated1998 · median 2004 among the 4,103 with a school on file
- Record last updated2024 · 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).
2,320 internal medicine physician records list a practice address in Boston
They are 2,320 of the 41,865 NPPES records with a practice address in Boston, and 6,825 internal medicine physician records in Massachusetts. No Medicare prescribing, quality score, industry payment or hospital affiliation is published for this NPI.
All 6,825 in Massachusetts → Every provider in Boston → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Daniel Alford, M.D., M.P.H.Boston, MA 021181194708628
- Lori Balestrero, MDBoston, MA 021181750384046
- Virginia Barrow, M.D.Boston, MA 021181639175466
- Monica Bharel, MDBoston, MA 021181093798084
- Claire Carlo, M.D.Boston, MA 021181336125871
- Chava Chapman, M.D., M.P.H.Boston, MA 021181558346239
- Paul Fallon, MDBoston, MA 021181437145927
- Irene Gavras, M.D.Boston, MA 021181619953601
Common questions
What is Janet C. Larson, M.D.'s NPI number?
Janet C. Larson, M.D.'s National Provider Identifier (NPI) is 1831159326, issued on Mar 27, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Janet C. Larson, M.D. located?
The NPPES record lists a practice address at 801 Massachusetts Ave, Boston, MA, 02118. Phone: (617) 414-7399. Providers update this record themselves, so call before visiting.
How can I verify Janet C. Larson, M.D.'s license?
NPPES lists Massachusetts license number 220603, 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.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. 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.