NPPES file of Aug 9, 2026

Mark D. Calayag, M.D.

Neurology with Special Qualifications in Child Neurology Physician · Orange, CA

Mark D. Calayag, M.D. is a neurology with special qualifications in child neurology physician with a practice address in Orange, California, and NPI 1336373901, issued on May 11, 2009. Check the license (California A137268, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.

Record from CMS NPPES, file of Aug 9, 2026 · Medicare files 2024 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1336373901
Name
Mark D. Calayag
Credential
M.D.
Primary taxonomy
Neurology with Special Qualifications in Child Neurology Physician 2084N0402X
License numbers
A137268 CA
137268 CA
Self-reported in NPPES; status is on the state search
Practice location
200 S Manchester Ave, Orange, CA 92868
Phone
(714) 456-6966
Enumerated
May 11, 2009
Record last updated
Jan 3, 2025
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 200 S Manchester Ave

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

  1. Al Aly, MDPlastic and Reconstructive Surgery Physician1154476588
  2. Nadia AraujoSpeech-Language Pathologist1245690478
  3. Julia Armstrong, MA, CCC-SLPSpeech-Language Pathologist1912368259
  4. Derek Banyard, M.D.Surgery Physician1194015313
  5. Michelle Boucher, PAPhysician Assistant1750337895
  6. Luis Chui, M.DNeuromusculoskeletal Medicine & OMM Physician1134210842

Verify Mark D. Calayag in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license A137268
    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

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95% fewer Medicare Part D claims than the average neurology with special qualifications in child neurology physician in 2024

14 Medicare Part D claims, against an average of 278 among the 900 providers of this specialty who prescribed in Part D.

  1. Mark Calayag14
  2. Specialty average278

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.

Mark D. Calayag among 271 neurology with special qualifications in child neurology physician records in California

Mark D. Calayag, M.D. is one of 271 neurology with special qualifications in child neurology physician records with a practice address in California. 67% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2009, is newer than 48% of them.

  • NPI issued2009 · 48% of these records are older, 48% newer
  • In a Medicare fileYes · 67% of these records are
  • In the CMS Doctors and Clinicians fileNo · 33% of these records are
  • Record last updated2025 · 45% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 2084N0402X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

Neurology with Special Qualifications in Child Neurology Physician providers in California

There are 271 neurology with special qualifications in child neurology physician records in California.

The 8 neurology with special qualifications in child neurology physician records with the nearest ZIP codes

  1. Jane Donat, M.D.Orange, CA 928681497723498
  2. Joseph Donnelly, MDOrange, CA 928681699719237
  3. Amanda Fernandez, M.D.Orange, CA 928681770551350
  4. Glenn Fowler, MDOrange, CA 928681104848274
  5. Sailaja Golla, MDOrange, CA 928681033309836
  6. Virginia Liu, M.D, PH.DOrange, CA 928681447639182
  7. Andrew McIntosh, MDOrange, CA 928681043233026
  8. Jonathan Megerian, M.D., PH.D.Orange, CA 928681124065891

Common questions

What is Mark D. Calayag, M.D.'s NPI number?

Mark D. Calayag, M.D.'s National Provider Identifier (NPI) is 1336373901, issued on May 11, 2009. An NPI identifies a provider in billing; it is not a license.

Where is Mark D. Calayag, M.D. located?

The NPPES record lists a practice address at 200 S Manchester Ave, Orange, CA, 92868. Phone: (714) 456-6966. Providers update this record themselves, so call before visiting.

How can I verify Mark D. Calayag, M.D.'s license?

NPPES lists California license number A137268, 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 Mark D. Calayag, M.D. prescribe under Medicare Part D?

In 2024, Mark D. Calayag, M.D. had 14 Medicare Part D claims; the average among neurology with special qualifications in child neurology physician prescribers was 278. 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.