Michael Tieu Loi, DO

Primary specialty

Internal Medicine PhysicianTaxonomy code 207R00000X

License

20A22634 Issued in CA

Practice address

11 Technology Dr
Irvine, CA 92618-2302

Phone

(949) 923-3200

NPI assigned

May 8, 2019

Last updated

Nov 23, 2025By the provider in NPPES

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 CA

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 Osteopathy

State licenses

Practice roles

Locations

Interoperability endpoints

• Direct secure messaging: michael.loi.p33@direct.monarchhealthcare.nextgenshare.com
• Direct secure messaging: mloi1222130@direct.llu.edu
• Direct secure messaging: mloi855579@direct.memorialcare.org

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

• Centers for Family Medicine GP

  dba Optumcare Medical Group

  • Family Medicine Physician
  • Los Alamitos, CA
  • NPI 1467598243

  Internal Medicine

  Medicare reassignment NPD
• Healthcare Partners Affiliates Medical Group

  dba Optum

  • Internal Medicine Physician
  • Los Angeles, CA
  • NPI 1659312593
  Medicare reassignment NPD
• Riverside Faculty Medical Group Inc

  • Internal Medicine Physician
  • Moreno Valley, CA
  • NPI 1124032461
  Medicare reassignment NPD
• Healthcare Partners Affiliates Medical Group

  dba Optum

  • Durable Medical Equipment & Medical Supplies
  • Murrieta, CA
  • NPI 1760057269
  NPD

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

{
    "created_epoch": "1557273600000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1763856000000",
    "number": "1861057556",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "PO BOX 35380",
            "city": "LAS VEGAS",
            "state": "NV",
            "postal_code": "891335380",
            "telephone_number": "702-579-3203"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "11 TECHNOLOGY DR",
            "city": "IRVINE",
            "state": "CA",
            "postal_code": "926182302",
            "telephone_number": "949-923-3200"
        }
    ],
    "practiceLocations": [],
    "basic": {
        "last_name": "LOI",
        "first_name": "MICHAEL",
        "middle_name": "TIEU",
        "name_prefix": "Dr.",
        "credential": "DO",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2019-05-08",
        "last_updated": "2025-11-23",
        "certification_date": "2025-11-23",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207R00000X",
            "taxonomy_group": "",
            "desc": "Internal Medicine",
            "state": "CA",
            "license": "20A22634",
            "primary": true
        },
        {
            "code": "390200000X",
            "taxonomy_group": "",
            "desc": "Student in an Organized Health Care Education/Training Program",
            "state": null,
            "license": null,
            "primary": false
        }
    ],
    "identifiers": [],
    "endpoints": [],
    "other_names": []
}

• Andrea Lochtefeld, ACSW
• Anne Lockary
• Lodespoto Medical of California PC
• Bellamy Loefman
• Kasey Loftus
• Arpita Mandal Loiacano, LEP
• Hether L Lombardo-Benjamin, LMFT
• Delanie R Lombardo
• Kathleen Joy Gozum Lombardo, DPT
• Jose M Lomboy, DDS

• Internal Medicine Physician in Irvine, CA
• Providers in Irvine, CA by specialty
• Internal Medicine Physician in California

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Nov 23, 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.