Fred Vonstieff, M.D.
NPI 1790849685 · Addiction Medicine (Family Medicine) Physician · Concord, CA
Enrolled with Medicare as Practitioner - Addiction Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Fred Vonstieff, M.D. is a Addiction Medicine (Family Medicine) Physician provider in Concord, CA (NPI 1790849685).
Provider details
- NPI number
- 1790849685
- Entity type
- Individual
- Primary specialty
- Addiction Medicine (Family Medicine) PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- Yes
- License
- G34928 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
19 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
377 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our .
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 35 Minutes99232 | 189 | $88 |
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 50 Minutes99233 | 69 | $133 |
| Hospital Discharge Day Management, More Than 30 Minutes99239 | 62 | $130 |
| Initial Hospital Care With Moderate Level of Medical Decision Making, If Using Time, at Least 75 Minutes99223 | 57 | $193 |
Typical Medicare-allowed amounts for these services range $88–$193 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 21 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Trazodone Hcl | 75 | 51 |
| Gabapentin | 68 | 61 |
| Famotidine | 64 | 47 |
| Hydroxyzine Pamoate | 64 | 40 |
| Naltrexone Hcl | 57 | 33 |
| Pantoprazole Sodium | 34 | 18 |
| Quetiapine Fumarate | 28 | 20 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$27 across 1 record (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-12-21
- Last updated
- 2014-07-30
Frequently asked questions
- What is Fred Vonstieff's NPI number?
- Fred Vonstieff's National Provider Identifier (NPI) is 1790849685, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Fred Vonstieff's specialty?
- Fred Vonstieff is listed in the NPPES registry with a primary specialty of Addiction Medicine (Family Medicine) Physician (Allopathic & Osteopathic Physicians).
- Where is Fred Vonstieff located?
- Fred Vonstieff's practice location on file with NPPES is 2481 Pacheco St, Concord, CA 94520-2019.
- What is Fred Vonstieff's phone number?
- The practice phone number listed in the NPPES registry for Fred Vonstieff is (925) 680-8933.
- Does Fred Vonstieff accept Medicare?
- Fred Vonstieff is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Fred Vonstieff's NPI active?
- Yes — Fred Vonstieff's NPI (1790849685) is active in the NPPES registry as of the last update on 2014-07-30.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.