Jules Leonard Dienstag, MD

Primary specialty

Internal Medicine PhysicianTaxonomy code 207R00000X

License

42401 Issued in MA

Practice address

55 Fruit St
BLK 4, Gastroenterology Associates
Boston, MA 02114-2696

Phone

(617) 726-7450

Fax

(617) 726-3673

NPI assigned

Feb 7, 2006

Sex

Male

Sole proprietor

No

Registry information is reported by the provider to CMS and is not verified. About this source

Specialties & licenses 1

Addresses

Other identifiers 3

Medicare fee-for-service enrollment

Not listed in the public Medicare enrollment file

Eligible to order & refer

• Part B services: Yes
• Medical equipment: Yes
• Home health: Yes
• Power mobility devices: Yes
• Hospice: Yes

Green means eligible to order or refer.

Medicare enrollment (NPD)

Enrolled

Credentials

Doctor of Medicine

Practice roles

Locations

Interoperability endpoints

• Direct secure messaging: dienstag.jules.mgh@direct.partners.masshiway.net

Organizations this provider is connected to: Medicare benefit reassignments (the organization bills Medicare for this provider’s services), Care Compare group memberships and National Provider Directory roles.

• General Hospital Corp

  • General Acute Care Hospital
  • Boston, MA
  • NPI 1508390014
  NPD
• Massachusetts General Physicians Organization Inc

  • Dermatology Physician
  • Boston, MA
  • NPI 1801874573

  Internal Medicine

  NPD
• The General Hospital Corporation

  • General Acute Care Hospital
  • Boston, MA
  • NPI 1023049236
  NPD

The complete NPPES record for this NPI in the NPI Registry API format.

{
    "created_epoch": "1139270400000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1783900800000",
    "number": "1710959390",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "PO BOX 9142",
            "address_2": "MASS GENERAL PHYSICIAN ORGANIZATION",
            "city": "CHARLESTOWN",
            "state": "MA",
            "postal_code": "021299142",
            "telephone_number": "617-724-0287",
            "fax_number": "617-726-2894"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "55 FRUIT ST",
            "address_2": "BLK 4, GASTROENTEROLOGY ASSOCIATES",
            "city": "BOSTON",
            "state": "MA",
            "postal_code": "021142696",
            "telephone_number": "617-726-7450",
            "fax_number": "617-726-3673"
        }
    ],
    "practiceLocations": [],
    "basic": {
        "last_name": "DIENSTAG",
        "first_name": "JULES",
        "middle_name": "LEONARD",
        "name_prefix": "Dr.",
        "credential": "MD",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2006-02-07",
        "last_updated": "2026-07-13",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207R00000X",
            "taxonomy_group": "",
            "desc": "Internal Medicine",
            "state": "MA",
            "license": "42401",
            "primary": true
        }
    ],
    "identifiers": [
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "BCBS MA",
            "identifier": "M09697",
            "state": "MA"
        },
        {
            "code": "05",
            "desc": "MEDICAID",
            "issuer": null,
            "identifier": "2062798",
            "state": "MA"
        },
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "TUFTS HEALTH PLAN",
            "identifier": "042401",
            "state": "MA"
        }
    ],
    "endpoints": [],
    "other_names": []
}

• Brendan J Diederichs, MD
• Stephen Diefenderfer
• Paul Brian Dieffenbach, M.D.
• Brian William Diehl, LICSW
• Maribeth Diener, RN
• Bradford James Diephuis, M.D.
• Gillian Ruth Diercks, M.D.
• Kira A Dies, SCM
• Samantha Bobbi Dietel
• Laura Adriana Dietmann, PSYD

• Internal Medicine Physician in Boston, MA
• Providers in Boston, MA by specialty
• Internal Medicine Physician in Massachusetts

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Jul 13, 2026; self-reported and not verified by CMS. Specialty names from the NUCC taxonomy.
• Medicare enrollment (CMS PECOS): enrollments, PAC IDs and benefit reassignments; Order and Referring.
• National Provider Directory (CMS): practice roles, locations, licenses, networks and endpoints.

Verify at the official NPI Registry.