Matthew J Siekkinen, LCSW

Primary specialty

Clinical Social WorkerTaxonomy code 1041C0700X

License

34012446A Issued in IN

Practice address

239 Hillsdale Ave
Greencastle, IN 46135-1340

Phone

(765) 653-1024

NPI assigned

May 30, 2018

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 IN

Eligible to order & refer

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

Green means eligible to order or refer.

Enrollment records 1

Specialty

Clinical Social Worker

Education

Other, 2013

Medicare assignment

Accepts the Medicare-approved amount as payment in full

Group practices

Hamilton Center, Inc.Group PAC ID 4284533662, 42 clinicians

Practice addresses (Care Compare)

Medicare enrollment (NPD)

Enrolled

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.

• Hamilton Center, Inc.

  • Community/Behavioral Health Agency
  • Terre Haute, IN
  • NPI 1205980901
  Medicare reassignment Care Compare group NPD
• Hamilton Center Inc.

  • Methadone Clinic
  • Vincennes, IN
  • NPI 1265053854
  NPD
• Hamilton Center, Inc.

  • Community/Behavioral Health Agency
  • Terre Haute, IN
  • NPI 1649007774
  NPD (past)
• Meridian Health Services Corp

  • Psychiatric Hospital
  • Muncie, IN
  • NPI 1932340882
  NPD (past)
• Meridian Health Services Corp.

  • Federally Qualified Health Center (FQHC)
  • Montpelier, IN
  • NPI 1417838574
  NPD (past)

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

{
    "created_epoch": "1527638400000",
    "enumeration_type": "NPI-1",
    "last_updated_epoch": "1765152000000",
    "number": "1003308768",
    "addresses": [
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "MAILING",
            "address_type": "DOM",
            "address_1": "620 8TH AVE",
            "city": "TERRE HAUTE",
            "state": "IN",
            "postal_code": "478042771",
            "telephone_number": "812-231-8323"
        },
        {
            "country_code": "US",
            "country_name": "United States",
            "address_purpose": "LOCATION",
            "address_type": "DOM",
            "address_1": "239 HILLSDALE AVE",
            "city": "GREENCASTLE",
            "state": "IN",
            "postal_code": "461351340",
            "telephone_number": "765-653-1024"
        }
    ],
    "practiceLocations": [
        {
            "address_1": "2401 W University Ave Fl 3",
            "address_purpose": "LOCATION",
            "city": "Muncie",
            "state": "IN",
            "postal_code": "473033428",
            "country_code": "US",
            "telephone_number": "765-751-1701",
            "country_name": "United States",
            "address_type": "DOM"
        }
    ],
    "basic": {
        "last_name": "SIEKKINEN",
        "first_name": "MATTHEW",
        "middle_name": "J",
        "credential": "LCSW",
        "sole_proprietor": "NO",
        "sex": "M",
        "enumeration_date": "2018-05-30",
        "last_updated": "2025-12-08",
        "certification_date": "2025-12-08",
        "status": "A"
    },
    "taxonomies": [
        {
            "code": "1041C0700X",
            "taxonomy_group": "",
            "desc": "Social Worker, Clinical",
            "state": "IN",
            "license": "34012446A",
            "primary": true
        },
        {
            "code": "104100000X",
            "taxonomy_group": "",
            "desc": "Social Worker",
            "state": "IN",
            "license": "33007302A",
            "primary": false
        }
    ],
    "identifiers": [],
    "endpoints": [],
    "other_names": []
}

• Larry R Seybold, MS
• Ruth Marie Shalley, LCSW
• Jennifer D Sheffler, NP
• Matthew Dean Sheffler, CRNA
• Carlos Edward Shrewsbury
• James Anthony Skrabak, DO
• Abbigail B Smith, RD
• Loretta Jean Smith, ED.S.
• Mark Alan Smith, D.D.S.
• William Dixon Smith

• Clinical Social Worker in Greencastle, IN
• Providers in Greencastle, IN by specialty
• Clinical Social Worker in Indiana

• NPPES NPI Registry (CMS): identity, addresses, specialties, licenses, identifiers and endpoints. Last updated by the provider on Dec 8, 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.