MATTHEW J SIEKKINEN LCSW
NPI 1003308768
Social Worker - Clinical in Greencastle, IN
About Matthew J Siekkinen Lcsw NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
MATTHEW J SIEKKINEN LCSW (NPI 1003308768) is an individual clinical provider in Greencastle, Indiana, licensed in Indiana (34012446A) and active in the NPI registry since May 2018. He is enrolled in Medicare PECOS, maintains a secondary practice location in Muncie, and is a graduate of Other (2013).
NPPES Registry Identity
Specialties & Licenses 2
Secondary Practice Location 1
Accepted Insurance
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare and accepts Medicare assignment
Matthew J Siekkinen Lcsw is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.
Medicare Billing Reassignment
Medicare enrollment records show Matthew Siekkinen reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.
Terre Haute, IN 47804
- Reassigned Medicare billing, Indiana enrollment
- 85 clinicians in this Medicare group
Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
Physician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 46135 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Other Providers at the Same Location NPPES 9
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
GREENCASTLE, IN 46135
GREENCASTLE, IN 46135
Frequently Asked Questions NPPES & CMS
Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.
What is Matthew Siekkinen's NPI number?
The NPI number for Matthew Siekkinen is 1003308768. It was assigned to this individual provider in the NPPES registry on May 30, 2018.
Where is Matthew Siekkinen located?
Matthew Siekkinen practices at 239 Hillsdale Ave, Greencastle, IN 46135. The listed phone number is (765) 653-1024.
What is Matthew Siekkinen's specialty?
The primary specialty registered for this NPI is Social Worker, specializing in Clinical, with taxonomy code 1041C0700X.
Is Matthew Siekkinen enrolled in Medicare?
Yes. Matthew Siekkinen is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.
Which organization bills Medicare for Matthew Siekkinen's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Matthew Siekkinen reassigns Medicare benefits to Hamilton Center, Inc. (Terre Haute, IN). The reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Matthew Siekkinen's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
What insurance does Matthew Siekkinen accept?
Health plans from Anthem Blue Cross and Blue Shield and CareSource list Matthew Siekkinen as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.
When was this NPI record last updated?
The NPPES record for Matthew Siekkinen was last updated on December 8, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 10 months ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.
# Matthew J Siekkinen, LCSW · NPI 1003308768
Clinical provider in Greencastle, Indiana. Individual provider, active in the CMS NPPES registry since May 30, 2018.
## Identity
- **NPI:** 1003308768 (Entity type: Individual)
- **Enumerated:** May 30, 2018
- **Primary specialty:** Social Worker - Clinical · taxonomy 1041C0700X
- **State license:** 34012446A (Indiana)
- **Sole proprietor:** No
## Practice location
- **Address:** 239 HILLSDALE AVE, Greencastle, IN 46135-1340
- **Phone:** (765) 653-1024
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment
- **Bills Medicare through:** Hamilton Center, Inc. (NPI 1205980901, Terre Haute, IN), under Medicare reassignment (form CMS-855R) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2013
## Record status
- **NPPES last updated:** December 8, 2025
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Source: [NPI Profile](https://npiprofile.com/npi/1003308768) · Data from the CMS NPPES public registry.