NPPES file of Aug 9, 2026

Doctors and health care providers in Boston, MA

41,865 individual NPPES records list a practice address in Boston, 1st of 406 Massachusetts cities. The largest group is students in training: 6,126, 15% of the city's records, against 5% across Massachusetts. Page 123 of 838.

CMS NPPES registry, file of Aug 9, 2026 · method · Verify with CMS →

The 8 largest groups in Boston

Source: CMS NPPES primary taxonomy, file of Aug 9, 2026.

Boston in Massachusetts

  • Rank in Massachusetts1st of 406 cities by records
  • Share of the state19.1% of Massachusetts's records
  • Specialties present25 or more taxonomy codes
  • Top three groups24.7% of all records
  • Students in training rank1st of the 10 Massachusetts cities with the most

Compared with Massachusetts as a whole, Boston has 2.9× the state's share of student in an organized health care education/training program records and 0.23× its share of mental health counselor records.

Providers in Boston, alphabetically

  1. Cathleen CasilloCertified Registered Nurse Anesthetist1225656242
  2. Teresa CasimireMarriage & Family Therapist1760276240
  3. Rachel Caso, LICSWClinical Social Worker1922651199
  4. Kelly CasottanaStudent in an Organized Health Care Education/Training Program1891526000
  5. Jessica Casper, PA-CPhysician Assistant1255853917
  6. Shelby Casper, FNP-BCFamily Nurse Practitioner1821886144
  7. Melissa Casperson, CPNP-PCPediatric Nurse Practitioner1508375767
  8. Krysta CassSurgical Physician Assistant1679075410
  9. Maureen Cassady, MDPsychiatry Physician1386149797
  10. Nicole CassarinoPsychiatry Physician1427997600
  11. Mary Ann Cassel, M.A.Audiologist1396750709
  12. Anna Cassell, MD, MBA, MPHILHospitalist Physician1639756430
  13. Rachel Casseres, MDPsychiatry Physician1386272177
  14. Anilady Casserino, ARNPFamily Nurse Practitioner1407390636
  15. Morgan CassfordAudiologist1285567974
  16. Susan Cassiani, BSN,RN,CDEDiabetes Educator Registered Nurse1639682198
  17. Brett Cassidy, MDAnatomic Pathology & Clinical Pathology Physician1255126520
  18. Caroline Cassidy, PA-CPhysician Assistant1669165999
  19. Charles Cassidy, M.D.Orthopaedic Hand Surgery Physician1053351585
  20. Douglas CassidyStudent in an Organized Health Care Education/Training Program1487413746
  21. Michael Cassidy, M.D.Surgical Oncology Physician1114186905
  22. Ryan Cassidy, MDSurgery Physician1689377970
  23. Carolyn Cassill, PH.D.Psychologist1801479639
  24. Natalie Cassis, DDSGeneral Practice Dentistry1649686759
  25. Jenna Cassoli, LCSWClinical Social Worker1306238969
  26. Clark Cassone, MSN, FNP-BCNurse Practitioner1720335615
  27. Alfonso Casta, MDAnesthesiology Physician1861460149
  28. Peter Castaldi, M.D.Internal Medicine Physician1902891062
  29. Lorraine Castaldo, RDRenal Nutrition Registered Dietitian1144346016
  30. Carmen Castaneda MojenaDentist1881560720
  31. Morgan Castanet, CRNACertified Registered Nurse Anesthetist1427561919
  32. Juliana Castedo, MDFamily Medicine Physician1992191167
  33. Emily CasteenInternal Medicine Physician1215875570
  34. Shahar Castel, PA-CPhysician Assistant1275194490
  35. Flavia Castelino, M.D.Rheumatology Physician1962611301
  36. Alyssa Castellani, LCSWSocial Worker1740905686
  37. Daniel Castellanos, M.D.Pediatric Cardiology Physician1003298126
  38. Lina CastellanosStudent in an Organized Health Care Education/Training Program1356935480
  39. Mario Castellanos, MDEmergency Medicine Physician1164050910
  40. Juan Pablo Castello, MDStudent in an Organized Health Care Education/Training Program1366022675
  41. Chiara Castellucci, D.M.D.Dentist1649620873
  42. Enrico CastellucciStudent in an Organized Health Care Education/Training Program1821354622
  43. Federico Castellucci, D.M.D.Prosthodontics1861897175
  44. Coleen Caster, RN,C, MN, FNPFamily Nurse Practitioner1740448570
  45. Mark Castera, MDNeonatal-Perinatal Medicine Physician1649775396
  46. Natalie Castile, LCSWClinical Social Worker1699433714
  47. Cindy CastilloEndodontics1922663400
  48. David CastilloMental Health Counselor1841155447
  49. Elizabeth Castillo, MD PHDGeriatric Medicine (Internal Medicine) Physician1932176443
  50. Hector Castillo, MDOrthopaedic Surgery Physician1841819091

The largest Massachusetts cities

  1. Worcester13,166
  2. Springfield8,553
  3. Cambridge5,145
  4. Brockton4,287
  5. Milford3,459

All of Massachusetts →

How to read this directory

Boston, Massachusetts appears in the CMS National Plan and Provider Enumeration System with 41,865 registered healthcare providers spanning 25 or more distinct NUCC-taxonomy specialties. This count includes every individual clinician who has applied for an NPI and listed a practice address in Boston - physicians, dentists, nurse practitioners, physician assistants, chiropractors, physical therapists, optometrists, psychologists, podiatrists, and every other credentialed provider type CMS tracks. It does not measure hospital beds, urgent-care capacity, or whether a given clinic is accepting new patients; it measures the pool of professionals with current NPI enrollment and a Boston practice location on file. Every figure is drawn from the federal National Provider Identifier Registry (CMS NPPES) - more than 7 million providers, maintained since May 2007, with 2024 Medicare Part D data, and, according to CMS, can be searched, compared, and traced in our methodology.

The provider mix in Boston is weighted toward Student in an Organized Health Care Education/Training Program (6,126 clinicians, followed by Internal Medicine Physician with 2,320 and Clinical Social Worker with 1,906). That distribution reflects how NPPES records specialty: providers self-select a primary taxonomy code, so a family physician who also practices geriatrics will show up under whichever NUCC code they registered first. Relative to Massachusetts's population, Boston reports roughly 598 providers per 100,000 residents using the state-level denominator, which is a rough proxy rather than a precise access-to-care measurement; the true catchment area of any {cityName} clinician extends beyond the municipal boundary.

Of Massachusetts's most common specialties, Counselor is the most prominent one with no provider currently listing a Boston practice address, a coverage gap Boston patients typically fill by traveling to a larger nearby hub.

For Boston patients, this directory is most useful as a starting shortlist. Important: PlainDoctor is a directory of publicly available CMS government data, not a review site, a ranking, or medical advice. NPPES data is self-reported and refreshed monthly; call the practice directly to confirm the provider is still there, accepts your insurance, and is taking new patients.

For informational purposes only; this directory is not medical advice and not a substitute for checking a license. See also: how to find a doctor and how to verify one.

Common questions

How many doctors are in Boston, MA?

There are 41,865 registered healthcare providers in Boston, MA, covering 25 or more specialties. This includes physicians, dentists, therapists, and other licensed providers.

What are the most common medical specialties in Boston?

The most common specialties in Boston are Student in an Organized Health Care Education/Training Program, Internal Medicine Physician, Clinical Social Worker, Physician Assistant, Anesthesiology Physician. Student in an Organized Health Care Education/Training Program has the most providers with 6,126.

Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov). Records are self-reported registrations, not licenses.

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.