Timothy Ian Mackenzie Mercer, MD

Primary specialty

Internal Medicine PhysicianTaxonomy code 207R00000X

License

R4099 Issued in TX

Practice address

1601 Trinity St
Austin, TX 78712-1765

Phone

(512) 978-8130

NPI assigned

Aug 28, 2014

Sex

Male

Sole proprietor

No

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

Specialties & licenses 2

Addresses

Medicare fee-for-service enrollment

Enrolled in TX

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

Internal Medicine

Education

Indiana University School of Medicine, 2011

Medicare assignment

Accepts the Medicare-approved amount as payment in full

Group practices

Seton Family of DoctorsGroup PAC ID 0941333280, 785 clinicians

Travis County Healthcare DistrictGroup PAC ID 5890843858, 30 clinicians

Practice addresses (Care Compare)

Medicare enrollment (NPD)

Enrolled

Credentials

Doctor of Medicine

Practice roles

Locations

Interoperability endpoints

• Direct secure messaging: timothy.mercer@483269823102980.direct.elationemr.com

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.

• Seton Family of Doctors

  • Neurological Surgery Physician
  • Austin, TX
  • NPI 1588997233

  Internal Medicine

  Medicare reassignment Care Compare group NPD
• Travis County Healthcare District

  • Internal Medicine Physician
  • Austin, TX
  • NPI 1972271831
  Medicare reassignment Care Compare group NPD
• Seton Family of Doctors

  • Radiology Clinic/Center
  • Austin, TX
  • NPI 1275290694
  NPD

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

{
    "created_epoch": "1409184000000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1753488000000",
    "number": "1215337092",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "1601 TRINITY ST",
            "city": "AUSTIN",
            "state": "TX",
            "postal_code": "787121765"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "1601 TRINITY ST",
            "city": "AUSTIN",
            "state": "TX",
            "postal_code": "787121765",
            "telephone_number": "512-978-8130"
        }
    ],
    "practiceLocations": [
        {
            "address_1": "5339 N Ih 35 Ste 100",
            "address_purpose": "LOCATION",
            "city": "Austin",
            "state": "TX",
            "postal_code": "787232558",
            "country_code": "US",
            "telephone_number": "512-978-8130",
            "country_name": "United States",
            "address_type": "DOM"
        }
    ],
    "basic": {
        "last_name": "MERCER",
        "first_name": "TIMOTHY",
        "middle_name": "IAN MACKENZIE",
        "name_prefix": "Dr.",
        "credential": "MD",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2014-08-28",
        "last_updated": "2025-07-26",
        "certification_date": "2025-07-26",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "208000000X",
            "taxonomy_group": "",
            "desc": "Pediatrics",
            "state": "TX",
            "license": "R4099",
            "primary": false
        },
        {
            "code": "207R00000X",
            "taxonomy_group": "",
            "desc": "Internal Medicine",
            "state": "TX",
            "license": "R4099",
            "primary": true
        }
    ],
    "identifiers": [],
    "endpoints": [],
    "other_names": []
}

• Amber Mercer, MSN, RN, CPNP-PC
• Felicia De la Garza Mercer, PH.D.
• Jessica Nicole Mercer
• Joselyn Ruth Mercer, PA-C
• Patricia Mercer, LAC.
• Malik M Merchant, MD
• Merchants of Hope Charities, Inc.
• Merchants of Hope Community Mental Health Center
• Melinda Merck
• Trinity M Mereau, DPM

• Internal Medicine Physician in Austin, TX
• Providers in Austin, TX by specialty
• Internal Medicine Physician in Texas

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Jul 26, 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.
• 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.