Simon M. W. Lejeune, M.D.

Primary specialty

Psychiatry PhysicianTaxonomy code 2084P0800X

License

56687 Issued in MA

Practice address

77 Mass Ave E23
Mit Medical Center
Cambridge, MA 02139

Phone

(617) 253-2916

NPI assigned

Jun 1, 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

Medicare fee-for-service enrollment

Enrolled in MA

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.

Enrollment records 1

Specialty

Psychiatry

Education

Harvard Medical School, 1985

Medicare assignment

Accepts the Medicare-approved amount as payment in full

Group practices

Cambridge Public Health CommissionGroup PAC ID 8921910894, 654 clinicians

Practice addresses (Care Compare)

Merit-based Incentive Payment System (MIPS)

Final score

91.27 of 100Reported as group

Quality

77.51

Promoting interoperability

100

Improvement activities

40

Cost

76.72

Medicare enrollment (NPD)

Enrolled

Credentials

Doctor of Medicine

Practice roles

Locations

Interoperability endpoints

• Direct secure messaging: slejeune98186@direct.challiance.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.

• Cambridge Public Health Commission

  • General Acute Care Hospital
  • Cambridge, MA
  • NPI 1487603585
  Medicare reassignment Care Compare group NPD
• Cambridge Public Health Commission

  • General Acute Care Hospital
  • Cambridge, MA
  • NPI 1932313228
  NPD

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

{
    "created_epoch": "1149120000000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1783900800000",
    "number": "1821035403",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "74 BEALS ST",
            "address_2": "APT. #2",
            "city": "BROOKLINE",
            "state": "MA",
            "postal_code": "024466011",
            "telephone_number": "617-253-2916"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "77 MASS AVE E23",
            "address_2": "MIT MEDICAL CENTER",
            "city": "CAMBRIDGE",
            "state": "MA",
            "postal_code": "02139",
            "telephone_number": "617-253-2916"
        }
    ],
    "practiceLocations": [],
    "basic": {
        "last_name": "LEJEUNE",
        "first_name": "SIMON M. W.",
        "credential": "M.D.",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2006-06-01",
        "last_updated": "2026-07-13",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "2084P0800X",
            "taxonomy_group": "",
            "desc": "Psychiatry & Neurology, Psychiatry",
            "state": "MA",
            "license": "56687",
            "primary": true
        }
    ],
    "identifiers": [],
    "endpoints": [],
    "other_names": []
}

• Joan Barbara Leibovich, LICSW
• Belinda Leick
• Jonathon Moses Leiner
• Madeline Leite
• Karen Debra Leitner, M.D.
• Holly Lem, PH.D
• Rachael C Lemire
• Jillian Lemma
• Lemon Tree Therapy LLC
• Deborah Lemont, LIC. AC.

• Psychiatry Physician in Cambridge, MA
• Providers in Cambridge, MA by specialty
• Psychiatry 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.
• Medicare Care Compare (CMS): clinician profile, group practices, facility affiliations, MIPS scores and star ratings.
• National Provider Directory (CMS): practice roles, locations, licenses, networks and endpoints.

Verify at the official NPI Registry.