Registry data as of Aug 27, 2026

Katarzyna Tesmer, MD

Neonatal-Perinatal Medicine Physician · Orange, CA

Katarzyna Tesmer, MD is a neonatal-perinatal medicine physician with a practice address in Orange, California, and NPI 1679662753, issued on Oct 12, 2006. Check the license (California A53721, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.

Record from CMS NPPES, loaded Aug 27, 2026 · Medicare files 2023 and 2024 · method · Verify with CMS →

NPPES recordas of Aug 27, 2026
1679662753
Name
Katarzyna Tesmer
Credential
MD
Primary taxonomy
Neonatal-Perinatal Medicine Physician 2080N0001X
License number
A53721 CA
Self-reported in NPPES; status is on the state search
Practice location
455 S Main St, Orange, CA 92868
Phone
(714) 532-8620
Enumerated
Oct 12, 2006
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). A record is not a license: verify it with the state board.
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Also registered at 455 S Main St

A shared address usually means a shared clinic or building; it does not show who employs whom.

  1. Jose Abdenur, M.D.Clinical Biochemical Genetics Physician1154428027
  2. Eileen Abejar, PNPRegistered Nurse1083865042
  3. Felice Adler-Shohet, M.D.Pediatric Infectious Diseases Physician1962513051
  4. Irfan Ahmad, MDPediatrics Physician1699790139
  5. Sana Al-Jundi, M.D.Pediatric Critical Care Medicine Physician1912090465
  6. Ragnar Amlie, M.D.Neonatal-Perinatal Medicine Physician1972696433

Verify Katarzyna Tesmer in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license A53721
    Check the board
  3. 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
  4. 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
  5. 5CertificationBoard certificationABMS, AOA, NCCPA, AANPNot checked
Open the California license search

PlainDoctor does not match the HHS-OIG exclusion list to individual records: most entries carry no NPI. Search the OIG exclusion list by name.

Statewide context: the Medical Board of California reported 374 disciplinary actions in FY 2022-23. California discipline data →

82% fewer Medicare Part D claims than the average neonatal-perinatal medicine physician in 2024

12 Medicare Part D claims, against an average of 68 among the 157 providers of this specialty who prescribed in Part D.

  1. Katarzyna Tesmer12
  2. Specialty average68

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: $218.75

12 payments, mostly food and beverage; the largest payer was Revance Therapeutics, Inc.. The 644 providers of this specialty with any payment received $760.10 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.

  1. Katarzyna Tesmer$218.75
  2. Specialty average$760.10

Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.

Neonatal-Perinatal Medicine Physician providers in California

There are 630 neonatal-perinatal medicine physician records in California.

Other neonatal-perinatal medicine physician records in California

  1. Afshan Abbasi, M.D.Los Angeles, CA1831214428
  2. Ahmad Aboaziza, M.D.Visalia, CA1932442944
  3. Maria Abrantes, MDAnaheim, CA1861438889
  4. Harry Ackley, M.D.Menlo Park, CA1588697478
  5. Marian Adams, MDSan Jose, CA1457452740
  6. Prashant Agarwal, M.D.Madera, CA1770714834
  7. Bimal Agrawal, M.D.Los Angeles, CA1932341096
  8. Vikash AgrawalLoma Linda, CA1619383163
  9. David Aguilar, MDFresno, CA1184723157
  10. Amardeep Ahluwalia, MDSacramento, CA1245328988

Common questions

What is Katarzyna Tesmer, MD's NPI number?

Katarzyna Tesmer, MD's National Provider Identifier (NPI) is 1679662753, issued on Oct 12, 2006. An NPI identifies a provider in billing; it is not a license.

Where is Katarzyna Tesmer, MD located?

The NPPES record lists a practice address at 455 S Main St, Orange, CA, 92868. Phone: (714) 532-8620. Providers update this record themselves, so call before visiting.

How can I verify Katarzyna Tesmer, MD's license?

NPPES lists California license number A53721, 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 Katarzyna Tesmer, MD prescribe under Medicare Part D?

In 2024, Katarzyna Tesmer, MD had 12 Medicare Part D claims; the average among neonatal-perinatal medicine physician prescribers was 68. Part D covers Medicare prescriptions only.

Source: CMS National Plan and Provider Enumeration System (NPPES), loaded Aug 27, 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.

Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 27, 2026.