William Joseph Frericks, DDS

Primary specialty

DentistTaxonomy code 122300000X

Practice address

500 N Michigan Ave
Ste 520
Chicago, IL 60611-3755

Phone

(312) 337-4424

Fax

(312) 822-0877

NPI assigned

Jun 1, 2005

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

Not listed in the public Medicare enrollment file

Eligible to order & refer

• Part B services: Yes
• Medical equipment: Yes
• Home health: Yes
• Power mobility devices: No
• Hospice: Yes

Green means eligible to order or refer.

Opted out of Medicare

Yes, effective Nov 4, 2015 through Nov 4, 2027

Medicare enrollment (NPD)

Not enrolled

State licenses

Practice roles

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.

• William J Frericks, DDS, LTD

  • Dentist
  • Chicago, IL
  • NPI 1790204386
  NPD (past) Authorized official

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

{
    "created_epoch": "1117584000000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1783900800000",
    "number": "1427050608",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "500 N MICHIGAN AVE",
            "address_2": "STE 520",
            "city": "CHICAGO",
            "state": "IL",
            "postal_code": "606113755",
            "telephone_number": "312-337-4424",
            "fax_number": "312-822-0877"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "500 N MICHIGAN AVE",
            "address_2": "STE 520",
            "city": "CHICAGO",
            "state": "IL",
            "postal_code": "606113755",
            "telephone_number": "312-337-4424",
            "fax_number": "312-822-0877"
        }
    ],
    "practiceLocations": [],
    "basic": {
        "last_name": "FRERICKS",
        "first_name": "WILLIAM",
        "middle_name": "JOSEPH",
        "name_prefix": "Dr.",
        "credential": "DDS",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2005-06-01",
        "last_updated": "2026-07-13",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "122300000X",
            "taxonomy_group": "",
            "desc": "Dentist",
            "state": "IL",
            "license": null,
            "primary": true
        }
    ],
    "identifiers": [],
    "endpoints": [],
    "other_names": []
}

• Alexandra Frenn, LCSW
• Keely Frens
• Eugene Frenzel
• Ashley Frer, D.C.
• Denise A. Frer, ED.D., CH, CHTP
• Lee A Frerker, PA
• Ruben Frescas Jr., M.D., M.P.H.
• Joseph William Frescura, PA-C
• William A Frese, MD
• Fresenius Medical Care Chatham, LLC

• Dentist in Chicago, IL
• Providers in Chicago, IL by specialty
• Dentist 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; Opt Out Affidavits.
• National Provider Directory (CMS): practice roles, locations, licenses, networks and endpoints.

Verify at the official NPI Registry.