Curtis W Siu, MD

Primary specialty

Internal Medicine PhysicianTaxonomy code 207R00000X

License

A74829 Issued in CA

Practice address

23521 Paseo de Valencia Ste 108
Laguna Hills, CA 92653-3137

Phone

(949) 872-5227

Fax

(949) 588-2167

NPI assigned

Mar 15, 2006

Last updated

Apr 29, 2026By 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 1

Addresses

Medicare fee-for-service enrollment

Enrolled in CA

Enrollment records 1

Specialty

Internal Medicine

Education

University of California, San Diego School of Medicine, 1999

Medicare assignment

May accept Medicare assignment

Telehealth

Offers telehealth services

Practice addresses (Care Compare)

Hospital & facility affiliations

• Oasis Haven Hospice, Inc Hospice, Irvine, CA, CCN 751799
• Memorialcare Saddleback Medical Center Hospital, Laguna Hills, CA, CCN 050603

Merit-based Incentive Payment System (MIPS)

Final score

87.98 of 100Reported as individual

Quality

87.84

Promoting interoperability

95

Improvement activities

40

Cost

76.25

Medicare enrollment (NPD)

Enrolled

Credentials

Doctor of Medicine

State licenses

Practice roles

Locations

Networks

• BSC 65 PLUS INDIVIDUAL MAPD

Interoperability endpoints

• Direct secure messaging: csiu194713@westdirect.optum.com
• Direct secure messaging: curtis.siu.p15@direct.monarchhealthcare.nextgenshare.com

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.

• Healthcare Partners Affiliates Medical Group

  dba Optum

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

  • Gastroenterology Physician
  • Laguna Hills, CA
  • NPI 1386605822
  Medicare reassignment NPD
• Curtis Siu MD Inc

  • Internal Medicine Physician
  • Laguna Hills, CA
  • NPI 1316880586
  NPD Authorized official
• Healthcare Partners Affiliates Medical Group

  dba Optum

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

  • Rehabilitation Hospital Unit
  • Laguna Hills, CA
  • NPI 1114967114
  NPD (past)
• Southern California Hospitalist Network Medical Group Inc

  • Internal Medicine Physician
  • Orange, CA
  • NPI 1790880458
  NPD (past)
• Memorial Medical Group Inc

  • Durable Medical Equipment & Medical Supplies
  • Phoenix, AZ
  • NPI 1255523643
  NPD (past)

Hospitals and other facilities this clinician is affiliated with according to Medicare Care Compare.

• Oasis Haven Hospice, Inc.

  • Community Based Hospice Care Agency
  • Irvine, CA
  • NPI 1992115265
  Care Compare affiliation Name & address match
• Saddleback Memorial Medical Center

  • General Acute Care Hospital
  • Laguna Hills, CA
  • NPI 1275576381
  Care Compare affiliation

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

{
    "created_epoch": "1142380800000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1777420800000",
    "number": "1386613081",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "23521 PASEO DE VALENCIA STE 108",
            "city": "LAGUNA HILLS",
            "state": "CA",
            "postal_code": "926533137",
            "telephone_number": "949-872-5227"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "23521 PASEO DE VALENCIA STE 108",
            "city": "LAGUNA HILLS",
            "state": "CA",
            "postal_code": "926533137",
            "telephone_number": "949-872-5227",
            "fax_number": "949-588-2167"
        }
    ],
    "practiceLocations": [],
    "basic": {
        "last_name": "SIU",
        "first_name": "CURTIS",
        "middle_name": "W",
        "name_prefix": "Dr.",
        "credential": "MD",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2006-03-15",
        "last_updated": "2026-04-29",
        "certification_date": "2026-04-29",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207R00000X",
            "taxonomy_group": "",
            "desc": "Internal Medicine",
            "state": "CA",
            "license": "A74829",
            "primary": true
        }
    ],
    "identifiers": [],
    "endpoints": [],
    "other_names": []
}

• Akil Peter Simon, M.D.
• Sims in-Home Physical Therapy
• John Sims, P.T.
• Gregory Garabed Simsarian, M.D
• Karan J Singh, M.D.
• Kyle Sivcovich, PPSC
• Robert Barry Sklar, M.D.
• Gail S Skoropad, DPT
• Karen P. Skvarna, O.D.
• Sleep & Research Centers of Southern California, LLC

• Internal Medicine Physician in Laguna Hills, CA
• Providers in Laguna Hills, 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 Apr 29, 2026; self-reported and not verified by CMS. Specialty names from the NUCC taxonomy.
• Medicare enrollment (CMS PECOS): enrollments, PAC IDs and benefit reassignments.
• 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.