Steven R. Tolkan, MD
Nephrology Physician · Fairfield, CA
Steven R. Tolkan, MD is a nephrology physician with a practice address in Fairfield, California, and NPI 1871554766, issued on Mar 30, 2006. Check the license (California G83696, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Steven R. Tolkan
- Credential
- MD
- Primary taxonomy
- Nephrology Physician 207RN0300X
- License number
- G83696 CA
Self-reported in NPPES; status is on the state search - Practice location
- 1525 Webster St Ste A, Fairfield, CA 94533
- Phone
- (707) 423-2506
- Enumerated
- Mar 30, 2006
- Record last updated
- Apr 24, 2014 (not updated in 12 years: call before relying on the address or phone)
- Fax
- (707) 429-1158
- Medicare enrollment
- Enrolled (PECOS I20081027000652); may accept Medicare assignment
- Medical or professional school
- University Of Wisconsin School Of Medicine, 1973
- Entity
- Type 1 · individual
8 nearest nephrology physician records → All 1,468 in California → Look up another NPI →
Also registered at 1525 Webster St Ste A
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Margaret Difelice, PA CMedical Physician Assistant1356489678
Verify Steven R. Tolkan in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license G83696Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
48% fewer Medicare Part D claims than the average nephrology physician in 2024
756 Medicare Part D claims for 70 beneficiaries, against an average of 1,465 among the 10,986 providers of this specialty who prescribed in Part D. Brand-name drugs were 12% of claims. 94 claims were for opioids.
Most prescribed
- Losartan Potassium76 claims
- Sevelamer Carbonate60 claims
- Oxycodone-Acetaminophen55 claims
- Calcitriol32 claims
- Gabapentin26 claims
- Furosemide23 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Industry payments in 2024: $385.98
14 payments; by number, the most common kind was food and beverage; the largest payer was Amgen Inc. The 8,230 providers of this specialty with any payment received $3,091.37 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Steven R. Tolkan among 1,468 nephrology physician records in California
Steven R. Tolkan, MD is one of 1,468 nephrology physician records with a practice address in California. 88% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 10% of them.
- NPI issued2006 · 10% of these records are older, 48% newer
- In a Medicare fileYes · 88% of these records are
- In the CMS Doctors and Clinicians fileYes · 77% of these records are
- Graduated1973 · median 2001 among the 1,128 with a school on file
- Record last updated2014 · 62% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RN0300X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Nephrology Physician providers in California
There are 1,468 nephrology physician records in California.
All 1,468 in California → Every provider in Fairfield → Nephrology Physician nationwide →
The 8 nephrology physician records with the nearest ZIP codes
- Jack Luo, MDFairfield, CA 945341851920854
- Steven Ong, MDFairfield, CA 945341225006349
- Oleg Rubin, MDFairfield, CA 945341790762763
- John Baron, D.O.Travis Afb, CA 945351861471591
- Todd Bruno, M.D.Travis Afb, CA 945351407059702
- Madison Calder, MDFairfield, CA 945351336773571
- Fedoua Er Rbii, MDTravis Afb, CA 945351871150680
- Sharon Kang, M.D.Antioch, CA 945311487828471
Common questions
What is Steven R. Tolkan, MD's NPI number?
Steven R. Tolkan, MD's National Provider Identifier (NPI) is 1871554766, issued on Mar 30, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Steven R. Tolkan, MD located?
The NPPES record lists a practice address at 1525 Webster St Ste A, Fairfield, CA, 94533. Phone: (707) 423-2506. Providers update this record themselves, so call before visiting.
How can I verify Steven R. Tolkan, MD's license?
NPPES lists California license number G83696, as entered by the provider. Search the Medical Board of California at https://www.mbc.ca.gov/License-Verification/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Steven R. Tolkan, MD prescribe under Medicare Part D?
In 2024, Steven R. Tolkan, MD had 756 Medicare Part D claims for 70 beneficiaries; the average among nephrology physician prescribers was 1,465. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.