NPPES file of Aug 9, 2026

Internal Medicine Physician in Massachusetts

6,825 NPPES records list internal medicine physician with a practice address in Massachusetts, 97 per 100,000 residents, the 2nd highest rate of 51. Boston and Worcester have the most; each record links to the provider's NPI and the Massachusetts license search. Page 90 of 137.

CMS NPPES registry, file of Aug 9, 2026; 2023 Census estimates · NUCC 207R00000X · method

Written with AI tools from the named public files; every figure is computed from those files (how it is made).

Boston has the most, 2,320

  1. Boston2,320
  2. Worcester448
  3. Cambridge300
  4. Springfield282
  5. Burlington144

Internal Medicine Physician records in Massachusetts

  1. Robert O'Connor, M.D.Cambridge, MA 021381669768164
  2. Thomas O'Connor, M.D.Weymouth, MA 021891669507141
  3. William O'Connor, M.D.Millbury, MA 015271699756650
  4. John O'Dea, MB BCH BAOBoston, MA 021141669739975
  5. Elizabeth O'Donnell, MDBoston, MA 021141235396730
  6. Michael O'Donnell, MDBoston, MA 021181235759911
  7. Erin O'Hara, M.D.Gardner, MA 014401942407077
  8. Kelly O'Hara, M.D.Boston, MA 021181316171812
  9. Anna O'KellyBoston, MA 021141841656717
  10. Colin O'Leary, MDBoston, MA 021141588153456
  11. Daniel O'Leary, M.D.Leominster, MA 014531447346531
  12. Brian O'Malley, M.D.Provincetown, MA 026571083653646
  13. Barbara O'Neil, M.D.Cambridge, MA 021381275565335
  14. Kristin O'Neil-Callahan, M.D.Peabody, MA 019601215985445
  15. Sarah O'Shea, MDWestfield, MA 010851912269622
  16. Kathleen Oakes, MDBoston, MA 021111295437457
  17. Zaid Obaida, MDManassas, MA 011091073138517
  18. Aura Obando, M.D.Boston, MA 021181316268691
  19. Carla Oberst, M.D.Boston, MA 021091851337638
  20. Owen OboiteWorcester, MA 016051467941245
  21. Faruk Obut, M.D.Weymouth, MA 021901043661630
  22. Kimberly Ocallaghan, NPJamaica Plain, MA 021301881660561
  23. James Oconnell, MDBoston, MA 021181780661603
  24. John Oconnell, M.D.Fall River, MA 027201164430633
  25. Rosemary Oconnell, M.D.Boston, MA 021181871794784
  26. James Oconnor, MDNorth Falmouth, MA 025561891752572
  27. Raul Octaviani, M.D.Springfield, MA 011991831204890
  28. Tarek Odah, MDFramingham, MA 017021629599519
  29. Jeff Odiet, MDPeabody, MA 019601093705832
  30. Timothy Odonnell, MDFramingham, MA 017021346206091
  31. Rosette Perseveranda Odulio, M.D.Longmeadow, MA 011061326111634
  32. Jana Oettinger, MDHaverhill, MA 018301437184587
  33. Pius Ogagan, MDMedford, MA 021551134107964
  34. Chiamaka Ogbo, M.DAttleboro, MA 027031588926331
  35. John Oghene, MDHyannis, MA 026011528421609
  36. Kathleen Ogrady, MDShrewsbury, MA 015451831141688
  37. Barbara Ogur, MDCambridge, MA 021391356408751
  38. Edwin Oh, M.D.Dorchester, MA 021241326451717
  39. Irina Ohanian, M.D.Wellesley, MA 024811154353423
  40. Ramael Ohiomoba, MD, MPHBoston, MA 021151912480286
  41. Andrea Ohldin, M.D.Leeds, MA 010531427025717
  42. Michael OhligerBoston, MA 021151073713269
  43. Anna OhlrichBoston, MA 021141386133718
  44. Sarah Ohnigian, MDBoston, MA 022151306406194
  45. Aderinola Ojengbede, MDBrockton, MA 023011730218785
  46. Tomoko OkadaJamaica Plain, MA 021301609293554
  47. Barbara Okeke, MD, PHDBoston, MA 021141265134043
  48. Emily Oken, MDChestnut Hill, MA 024671497706667
  49. Ross Okimoto, M.DBoston, MA 021111164652061
  50. Chidimma Okoli, M.D.Worcester, MA 016051972823870

Source: CMS NPPES, primary taxonomy 207R00000X: records by practice city and the list of records, file of Aug 9, 2026.

Massachusetts ranks 2 of 51 per resident

  1. District of Columbia133
  2. Massachusetts97
  3. Rhode Island94
  4. Connecticut73
  5. 50 states and D.C.44

Source: CMS NPPES, primary taxonomy 207R00000X by practice state, file of Aug 9, 2026; records per 100,000 residents, 2023 Census estimates.

74.5% of these records appear in a Medicare file, against 78.7% nationally

A Medicare file here is Part D prescribing (2024), a MIPS score (2023), an Open Payments record (2024) or Medicare group billing (CMS Doctors and Clinicians). A record outside them may still see patients: these files cover Medicare only.

  1. Massachusetts74.5%
  2. United States78.7%

Internal Medicine Physician records in Massachusetts, measured

  • In a Medicare file5,088 of 6,825 · 74.5% here, 78.7% nationally
  • In the CMS Doctors and Clinicians file4,103 · 60.1% here, 61.4% nationally
  • Not updated in five years or more4,346 · 63.7% here, 55.4% nationally
  • Median graduation year2004 · the 4,103 records with a school on file

Source: CMS NPPES, file of Aug 9, 2026 (primary taxonomy 207R00000X); CMS Medicare Part D Prescribers 2024, MIPS 2023, Open Payments 2024 and Doctors and Clinicians, matched by NPI.

What the count covers

6,825 NPPES records list internal medicine physician (207R00000X) as their primary taxonomy with a practice address in Massachusetts: 97 per 100,000 residents against 44 nationally (50 states and D.C.). Boston has 2,320 of them (34%).

A record is a registration a provider made and keeps up to date: it shows neither that the provider is licensed nor that they still practice there. The state's own license search is the check.

States with a similar number

  1. Illinois7,238
  2. Pennsylvania7,300
  3. Michigan5,735
  4. Ohio5,277

States with a similar rate per 100,000

  1. Rhode Island94.3
  2. Connecticut72.5
  3. Maryland63.2
  4. Hawaii62.9

The largest states

  1. California17,696
  2. New York12,067
  3. Florida10,151
  4. Texas9,175
  5. Pennsylvania7,300

Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy; 2023 Census population estimates. A registry record 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.