OAK MEDICAL SC
NPI 1669910345
Internal Medicine in Waukesha, WI
About Oak Medical Sc NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
OAK MEDICAL SC (NPI 1669910345) is a healthcare organization registered as an internal medicine in Waukesha, Wisconsin and active in the NPI registry since February 2017. The organization lists Mahtab Sidhu, Medical Director, as its authorized official.
NPPES Registry Identity
Specialties & Licenses 3
Group Practice 2
Accepted Insurance
Medicare Participation & PECOS CMS
Medicare enrollment and the clinicians who bill Medicare through this organization, from CMS.
Medicare Enrollment Status
Enrolled in Medicare (PECOS)
Oak Medical Sc is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).
Clinicians Billing Medicare Through This Organization
190Medicare enrollment records show 190 clinicians reassign Medicare billing to Oak Medical Sc, which bills Medicare for the services they deliver. Of these, 28 practice at this address and 70 within 10 miles. Listed here are the 20 practicing nearest to this location.
Clinicians by Medicare Specialty 10
Nearest to this location (20)
See all 190Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
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 Oak Medical Sc's NPI number?
The NPI number for Oak Medical Sc is 1669910345. It was assigned to this organization in the NPPES registry on February 2, 2017.
Where is Oak Medical Sc located?
Oak Medical Sc is located at N20w22961 Watertown Rd, Waukesha, WI 53186. The listed phone number is (262) 875-5070.
What is Oak Medical Sc's specialty?
The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.
Is Oak Medical Sc enrolled in Medicare?
Yes. Oak Medical Sc is registered in the Medicare PECOS enrollment system.
How many clinicians bill Medicare through Oak Medical Sc?
According to the CMS Revalidation Reassignment List (October 2026 release), 190 clinicians in 10 Medicare specialties reassign their Medicare billing to Oak Medical Sc. A 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 the clinician's services. The largest specialties are Nurse Practitioner (134), Internal Medicine (31) and Family Practice (11). Of these, 28 practice at this address and 70 within 10 miles. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
What insurance does Oak Medical Sc accept?
Health plans from Anthem Blue Cross and Blue Shield, Aspirus Health Plan, CareSource (Common Ground Healthcare), Quartz and Security Health Plan list Oak Medical Sc 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 Oak Medical Sc was last updated on June 2, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 4 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.
# Oak Medical Sc · NPI 1669910345
Internal Medicine organization in Waukesha, Wisconsin. Organization record, active in the CMS NPPES registry since February 2, 2017.
## Identity
- **NPI:** 1669910345 (Entity type: Organization)
- **Enumerated:** February 2, 2017
- **Primary specialty:** Internal Medicine · taxonomy 207R00000X
- **Organization subpart:** No
- **Authorized official:** Mahtab Sidhu, MEDICAL DIRECTOR
## Practice location
- **Address:** N20W22961 WATERTOWN RD, Waukesha, WI 53186-1308
- **Phone:** (262) 875-5070 · **Fax:** (866) 384-9486
## Medicare
- **Medicare:** Enrolled in Medicare (PECOS)
- **Clinicians billing through this organization:** 190 clinicians in 10 Medicare specialties reassign Medicare billing to this organization (form CMS-855R); largest: Nurse Practitioner (134), Internal Medicine (31), Family Practice (11); 28 practice at this address and 70 within 10 miles; [full list](https://npiprofile.com/npi/1669910345/clinicians) · CMS Revalidation Reassignment List, October 2026 release
## Record status
- **NPPES last updated:** June 2, 2026
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Source: [NPI Profile](https://npiprofile.com/npi/1669910345) · Data from the CMS NPPES public registry.