Mark Day, DO

Primary specialty

Family Medicine PhysicianTaxonomy code 207Q00000X

License

656 Issued in NV

Practice address

1655 E Cactus Ave Ste 400
Las Vegas, NV 89183-7723

Phone

(702) 724-8777

Fax

(702) 724-8749

NPI assigned

Jul 28, 2006

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 NV

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

Family Practice

Education

Des Moines University of Osteopathic Medicine and Health Sciences, 1990

Medicare assignment

Accepts the Medicare-approved amount as payment in full

Group practices

Optum Medical Group II Rhodes P CGroup PAC ID 4981687779, 296 clinicians

Practice addresses (Care Compare)

Hospital & facility affiliations

• Summerlin Hospital Medical Center Hospital, Las Vegas, NV, CCN 290041

Medicare enrollment (NPD)

Enrolled

Credentials

Doctor of Osteopathy

State licenses

Practice roles

Locations

Interoperability endpoints

• Direct secure messaging: mday119391@westdirect.optum.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.

• Optum Medical Group II Rhodes P C

  dba Southwest Medical

  • Internal Medicine Physician
  • Las Vegas, NV
  • NPI 1790329407
  Medicare reassignment Care Compare group NPD
• Southwest Medical Associates, Inc

  • Internal Medicine Physician
  • Las Vegas, NV
  • NPI 1659346005
  Medicare reassignment NPD
• Optum Medical Group Rhodes P C

  dba Optumcare Anesthesia

  • Anesthesiology Physician
  • Las Vegas, NV
  • NPI 1770556037
  NPD
• Desert Springs Hospital

  dba Desert Springs Hospital Medical Center

  • General Acute Care Hospital
  • Las Vegas, NV
  • NPI 1154317964
  NPD (past)
• North Vista Hospital LLC

  • Psychiatric Hospital Unit
  • North Las Vegas, NV
  • NPI 1619050549
  NPD (past)
• Spring Valley Medical Center

  • General Acute Care Hospital
  • Las Vegas, NV
  • NPI 1346230323
  NPD (past)

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

• Summerlin Hospital Medical Center L L C

  dba Summerlin Hospital Medical Center

  • General Acute Care Hospital
  • Las Vegas, NV
  • NPI 1831189638
  Care Compare affiliation
• Summerlin Hospital Medical Center L L C

  dba ER at South Summerlin, Extension of Summerlin Hospital

  • Emergency Care Clinic/Center
  • Las Vegas, NV
  • NPI 1861234619

  Hospital

  Care Compare affiliation

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

{
    "created_epoch": "1154044800000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1762387200000",
    "number": "1164436994",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "PO BOX 50698",
            "city": "HENDERSON",
            "state": "NV",
            "postal_code": "890740698",
            "telephone_number": "702-456-9100",
            "fax_number": "702-434-7354"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "1655 E CACTUS AVE STE 400",
            "city": "LAS VEGAS",
            "state": "NV",
            "postal_code": "891837723",
            "telephone_number": "702-724-8777",
            "fax_number": "702-724-8749"
        }
    ],
    "practiceLocations": [
        {
            "address_1": "56 N Pecos Rd",
            "address_2": "Ste A",
            "address_purpose": "LOCATION",
            "city": "Henderson",
            "state": "NV",
            "postal_code": "890740698",
            "country_code": "US",
            "telephone_number": "702-456-9100",
            "fax_number": "702-434-7354",
            "country_name": "United States",
            "address_type": "DOM"
        }
    ],
    "basic": {
        "last_name": "DAY",
        "first_name": "MARK",
        "credential": "DO",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2006-07-28",
        "last_updated": "2025-11-06",
        "certification_date": "2025-11-06",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207Q00000X",
            "taxonomy_group": "",
            "desc": "Family Medicine",
            "state": "NV",
            "license": "656",
            "primary": true
        }
    ],
    "identifiers": [],
    "endpoints": [],
    "other_names": []
}

• Dale S Day, PA-C
• Daymon Day III
• Geraldine Sheppard Day
• Madison Day
• Margie Day
• Samara Day, NP
• Sheila A Day
• Taylor Dawn Day
• Thomas Day, CPC INTERN
• Tiffany Day

• Family Medicine Physician in Las Vegas, NV
• Providers in Las Vegas, NV by specialty
• Family Medicine Physician in Nevada

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Nov 6, 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.