Robert Allan Alter, M.D.

Primary specialty

Geriatric Medicine (Internal Medicine) PhysicianTaxonomy code 207RG0300X

Practice address

2545 S King Dr
Chicago, IL 60616-2441

Phone

(312) 842-7117

Fax

(312) 326-2102

NPI assigned

Feb 23, 2006

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 IL

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 Medicine

State licenses

Practice roles

Locations

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.

• Advocate Health and Hospitals Corporation

  • Multi-Specialty Clinic/Center
  • Oak Brook, IL
  • NPI 1700824455
  Medicare reassignment NPD
• Advocate Health & Hospitals Corporation

  • Medical Specialty Clinic/Center
  • Oak Lawn, IL
  • NPI 1912936014
  NPD
• Advocate Health and Hospitals Corporation

  • Children's Hospital
  • Oak Lawn, IL
  • NPI 1508315516
  NPD

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

{
    "created_epoch": "1140652800000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1783900800000",
    "number": "1821064585",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "2311 W 22ND ST",
            "address_2": "SUITE 202",
            "city": "OAK BROOK",
            "state": "IL",
            "postal_code": "605231225",
            "telephone_number": "630-320-1160",
            "fax_number": "630-320-1231"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "2545 S KING DR",
            "city": "CHICAGO",
            "state": "IL",
            "postal_code": "606162441",
            "telephone_number": "312-842-7117",
            "fax_number": "312-326-2102"
        }
    ],
    "practiceLocations": [],
    "basic": {
        "last_name": "ALTER",
        "first_name": "ROBERT",
        "middle_name": "ALLAN",
        "credential": "M.D.",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2006-02-23",
        "last_updated": "2026-07-13",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "207R00000X",
            "taxonomy_group": "",
            "desc": "Internal Medicine",
            "state": "IL",
            "license": null,
            "primary": false
        },
        {
            "code": "207RG0300X",
            "taxonomy_group": "",
            "desc": "Internal Medicine, Geriatric Medicine",
            "state": "IL",
            "license": null,
            "primary": true
        }
    ],
    "identifiers": [],
    "endpoints": [],
    "other_names": []
}

• Alter Psychology PLLC
• Andrea Ruth Alter
• Carolyn Alter, PSYD
• Joe Alter, LCSW
• Lydia Alter
• Alternative Behavior Treatment Centers
• Alternative Health Group LLC
• Alternative Healthcare of Beverly Hills Chicago, Inc.
• Alternative Pride Wellness, LLC
• Alternative Schools Network

• Geriatric Medicine (Internal Medicine) Physician in Chicago, IL
• Providers in Chicago, IL by specialty
• Geriatric Medicine (Internal Medicine) Physician in Illinois

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Jul 13, 2026; 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.