DR. FRED JOHN VONSTIEFF M.D.
NPI 1790849685
Family Medicine - Addiction Medicine in Concord, CA
About Dr. Fred John Vonstieff M.d. NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. FRED JOHN VONSTIEFF M.D. (NPI 1790849685) is an individual addiction medicine provider in Concord, California, licensed in California (G34928) and active in the NPI registry since December 2006. He is enrolled in Medicare PECOS and is a graduate of Un Of California, Irvine, College Of Medicine (1976).
NPPES Registry Identity
Specialties & Licenses
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
Dr. Fred John Vonstieff M.d. 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 Fred Vonstieff reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.
Concord, CA 94520
- Reassigned Medicare billing, California enrollment
- 5 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.
Areas of Expertise CMS Part B claims 4
Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.
Physician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 94520 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 4
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
CONCORD, CA 94520
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 Fred Vonstieff's NPI number?
The NPI number for Fred Vonstieff is 1790849685. It was assigned to this individual provider in the NPPES registry on December 21, 2006.
Where is Fred Vonstieff located?
Fred Vonstieff practices at 2481 Pacheco St, Concord, CA 94520. The listed phone number is (925) 680-8933.
What is Fred Vonstieff's specialty?
The primary specialty registered for this NPI is Family Medicine, specializing in Addiction Medicine, with taxonomy code 207QA0401X.
Is Fred Vonstieff enrolled in Medicare?
Yes. Fred Vonstieff 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 Fred Vonstieff's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Fred Vonstieff reassigns Medicare benefits to Fred J Von Stieff MD A Professional Corporation (Concord, CA). 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 Fred Vonstieff's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
When was this NPI record last updated?
The NPPES record for Fred Vonstieff was last updated on July 30, 2014. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 12 years 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.
# Dr. Fred John Vonstieff, M.D. · NPI 1790849685
Addiction Medicine physician in Concord, California. Individual provider, active in the CMS NPPES registry since December 21, 2006.
## Identity
- **NPI:** 1790849685 (Entity type: Individual)
- **Enumerated:** December 21, 2006
- **Primary specialty:** Family Medicine - Addiction Medicine · taxonomy 207QA0401X
- **State license:** G34928 (California)
- **Sole proprietor:** Yes
## Practice location
- **Address:** 2481 PACHECO ST, Concord, CA 94520-2019
- **Phone:** (925) 680-8933 · **Fax:** (925) 680-7635
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** Fred J Von Stieff MD A Professional Corporation (NPI 1568769412, Concord, CA), under Medicare reassignment (form CMS-855R) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Un Of California, Irvine, College Of Medicine, class of 1976
## Record status
- **NPPES last updated:** July 30, 2014
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Source: [NPI Profile](https://npiprofile.com/npi/1790849685) · Data from the CMS NPPES public registry.