Tanguy Yann Seiwert, M.D.

Primary specialty

Medical Oncology PhysicianTaxonomy code 207RX0202X

License

D88003 Issued in MD

Practice address

9910 Franklin Square Dr Ste 2110
Baltimore, MD 21236-4902

Phone

(410) 933-6423

NPI assigned

Mar 6, 2007

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 names 1

• Dr. Tanguy Yann Seiwert Former name

Medicare fee-for-service enrollment

Enrolled in MD

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

Medicare enrollment (NPD)

Enrolled

Credentials

Doctor of Medicine

State licenses

Practice roles

Locations

Interoperability endpoints

• Direct secure messaging: tlimseiwert544192@direct.hopkinsmedicine.org

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.

• Johns Hopkins University

  • Pain Medicine (Anesthesiology) Physician
  • Baltimore, MD
  • NPI 1922008549
  Medicare reassignment NPD
• Johns Hopkins University

  • Ophthalmology Physician
  • Belcamp, MD
  • NPI 1376342774
  NPD
• Johns Hopkins University

  • Medical Oncology Physician
  • Baltimore, MD
  • NPI 1902896970
  NPD
• Frederick Health Hospital Inc

  • General Acute Care Hospital
  • Frederick, MD
  • NPI 1538165527
  NPD (past)

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

{
    "created_epoch": "1173139200000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1754956800000",
    "number": "1043340292",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "814 PARTIN WAY",
            "city": "GEORGETOWN",
            "state": "DE",
            "postal_code": "199478715",
            "telephone_number": "302-447-9009",
            "fax_number": "321-471-1136"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "9910 FRANKLIN SQUARE DR STE 2110",
            "city": "BALTIMORE",
            "state": "MD",
            "postal_code": "212364902",
            "telephone_number": "410-933-6423"
        }
    ],
    "practiceLocations": [],
    "basic": {
        "last_name": "SEIWERT",
        "first_name": "TANGUY",
        "middle_name": "YANN",
        "name_prefix": "Dr.",
        "credential": "M.D.",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2007-03-06",
        "last_updated": "2025-08-12",
        "certification_date": "2025-08-12",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207RX0202X",
            "taxonomy_group": "",
            "desc": "Internal Medicine, Medical Oncology",
            "state": "MD",
            "license": "D88003",
            "primary": true
        }
    ],
    "identifiers": [],
    "endpoints": [],
    "other_names": [
        {
            "first_name": "TANGUY",
            "last_name": "SEIWERT",
            "middle_name": "YANN",
            "prefix": "DR.",
            "credential": "M.D.",
            "code": "1",
            "type": "Former Name"
        }
    ]
}

• Tin Sein, MD
• Sarah Cauldwell Seipp-Williams
• Jenna Seiss, LGPC
• Kathleen Suzanne Seitz, OTR/L
• Simone R Seitz
• Priya Sekar, MD
• Anjana Sekaran
• Vuk Sekicki, M.D.
• Mahseeyahu Ben Selassie, LGSW
• Dena M Selby, M.D.

• Medical Oncology Physician in Baltimore, MD
• Providers in Baltimore, MD by specialty
• Medical Oncology Physician in Maryland

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Aug 12, 2025; 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.