NPIMap

Individual provider Active NPI

Gustavo Horacio Day, M.D.

  • Internal Medicine Physician
  • Dallas, TX
National Provider Identifier
1538239173
Registry record updated May 18, 2026
On this page

Key facts

NPPES NPI Registry
Primary specialty
Internal Medicine PhysicianTaxonomy code 207R00000X
License
K1411 Issued in TX
Practice address
7777 Forest LN
Building B, Suite416
Dallas, TX 75230-2505
Phone
(972) 566-6764
Fax
(972) 566-6968
NPI assigned
Nov 9, 2006
Sex
Male
Sole proprietor
Yes

NPPES NPI Registry

Updated by the provider on May 18, 2026

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

Specialties & licenses 1

Specialty (taxonomy)CodeLicenseStatePrimary
Internal Medicine Physician 207R00000X K1411 TX Primary

Addresses

Primary practice location

7777 Forest LN
Building B, Suite416
Dallas, TX 75230-2505

Mailing address

PO Box 738305
Dallas, TX 75373-8305
Phone (972) 566-6764

Other identifiers 3

IdentifierTypeStateIssuer
K1411OtherTXMEDICAL LICENSE
P00040AM6MedicaidTX
030243201MedicaidTX

Medicare participation

Medicare enrollment files
Medicare fee-for-service enrollment
Enrolled in TX
Eligible to order & refer
  • Part B services
  • Medical equipment
  • Home health
  • Power mobility devices
  • Hospice
Green means eligible to order or refer.

Enrollment records 1

Enrollment IDStateProvider typePAC IDDetails
I20080619000710 TX Practitioner - Internal Medicine 6204907165 Reassigns benefits to 1 organization

Care Compare profile

Medicare Care Compare
Specialty
Internal Medicine
Education
Other, 1990
Medicare assignment
May accept Medicare assignment

Practice addresses (Care Compare)

7777 Forest LN
Suite 416
Dallas, TX 75230-2571
Phone (972) 556-6764

Hospital & facility affiliations

National Provider Directory

National Provider Directory
Medicare enrollment (NPD)
Enrolled
Credentials
Doctor of Medicine

State licenses

LicenseStateTypeSpecialty
K1411TXMDInternal Medicine Physician

Practice roles

OrganizationSpecialtyStatusNew patients
Gustavo H Day MD PA Internal Medicine CurrentSince Feb 28, 2008 Accepting new patients

Locations

7777 Forest Ln
Ste B416
Dallas, TX 75230
Phone (214) 267-1400

7777 Forest Ln
Ste 416
Dallas, TX 75230
Phone (972) 556-6764

Interoperability endpoints

  • FHIR API: https://fhir4.healow.com/fhir/r4/FFGEAD/Endpoint/FFGEAD
  • FHIR API: https://fhir4.healow.com/fhir/r4/FFGEAD
  • Direct secure messaging: gustavo.day@gdim.eclinicaldirectplus.com

Organizations & group practices 1

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.

Hospital & facility affiliations 7

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

NPI Registry JSON

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

{
    "created_epoch": "1163030400000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1779062400000",
    "number": "1538239173",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "PO BOX 738305",
            "city": "DALLAS",
            "state": "TX",
            "postal_code": "753738305",
            "telephone_number": "972-566-6764",
            "fax_number": "972-566-6968"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "7777 FOREST LN",
            "address_2": "BUILDING B, SUITE416",
            "city": "DALLAS",
            "state": "TX",
            "postal_code": "752302505",
            "telephone_number": "972-566-6764",
            "fax_number": "972-566-6968"
        }
    ],
    "practiceLocations": [],
    "basic": {
        "last_name": "DAY",
        "first_name": "GUSTAVO",
        "middle_name": "HORACIO",
        "credential": "M.D.",
        "sole_proprietor": "YES",
        "sex": "M",
        "enumeration_date": "2006-11-09",
        "last_updated": "2026-05-18",
        "certification_date": "2026-05-18",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207R00000X",
            "taxonomy_group": "",
            "desc": "Internal Medicine",
            "state": "TX",
            "license": "K1411",
            "primary": true
        }
    ],
    "identifiers": [
        {
            "code": "01",
            "desc": "Other (non-Medicare)",
            "issuer": "MEDICAL LICENSE",
            "identifier": "K1411",
            "state": "TX"
        },
        {
            "code": "05",
            "desc": "MEDICAID",
            "issuer": null,
            "identifier": "P00040AM6",
            "state": "TX"
        },
        {
            "code": "05",
            "desc": "MEDICAID",
            "issuer": null,
            "identifier": "030243201",
            "state": "TX"
        }
    ],
    "endpoints": [],
    "other_names": []
}

Other providers in Dallas, TX

Sources for this page

Verify at the official NPI Registry.