Isabelle Barnard Moonan, M.D.
Gastroenterology Physician · Monterey, CA
Isabelle Barnard Moonan, M.D. is a gastroenterology physician with a practice address in Monterey, California, and NPI 1568472298, issued on Aug 8, 2006. Check the license (California A51122, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Isabelle Barnard Moonan
- Credential
- M.D.
- Primary taxonomy
- Gastroenterology Physician 207RG0100X
- License number
- A51122 CA
Self-reported in NPPES; status is on the state search - Practice location
- 23 Upper Ragsdale Dr, Monterey, CA 93940
- Phone
- (831) 375-3577
- Enumerated
- Aug 8, 2006
- Record last updated
- Dec 18, 2020 (not updated in 6 years: call before relying on the address or phone)
- Fax
- (831) 375-1478
- Medicare enrollment
- Enrolled (PECOS I20080524000052); accepts Medicare assignment
- Medical or professional school
- Clvlnd Clinic Lerner College Of Med Of Case Wstn Rsv University, 1991
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest gastroenterology physician records → All 2,140 in California → Look up another NPI →
Also registered at 23 Upper Ragsdale Dr
A shared address usually means a shared clinic or building; it does not show who employs whom.
- James Di Sario, M.D.Gastroenterology Physician1376553180
- Megan Fulton, CRNACertified Registered Nurse Anesthetist1457983801
- Lloyd Garren, M.D.Gastroenterology Physician1841200565
- Mary Garren, M.D.Gastroenterology Physician1801806567
- Silvia Giachetti, NPFamily Nurse Practitioner1427586189
- Richard Hell, M.D.Gastroenterology Physician1114937927
Verify Isabelle Barnard Moonan in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A51122Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
24% fewer Medicare Part D claims than the average gastroenterology physician in 2024
620 Medicare Part D claims for 258 beneficiaries, against an average of 811 among the 16,445 providers of this specialty who prescribed in Part D. Brand-name drugs were 6% of claims.
Most prescribed
- Omeprazole189 claims
- Famotidine92 claims
- Peg 3350-Electrolyte77 claims
- Pantoprazole Sodium72 claims
- Sod Sulf-Potass Sulf-Mag Sulf42 claims
- Mesalamine22 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.
The practice group's MIPS final score for 2023 (Medicare payment program): 83.8 of 100
The Merit-based Incentive Payment System score is reported for the practice group, not for one clinician alone. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).
Industry payments in 2024: $30.14
1 payment: food and beverage; the largest payer was Abbvie Inc. The 13,350 providers of this specialty with any payment received $5,015.95 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.
Bills Medicare through one group practice
- Monterey Bay GI Consultants Medical Group IncMonterey, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Isabelle Barnard Moonan among 2,140 gastroenterology physician records in California
Isabelle Barnard Moonan, M.D. is one of 2,140 gastroenterology physician records with a practice address in California. 83% 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 7% of them.
- NPI issued2006 · 7% of these records are older, 48% newer
- In a Medicare fileYes · 83% of these records are
- In the CMS Doctors and Clinicians fileYes · 72% of these records are
- Graduated1991 · median 2002 among the 1,538 with a school on file
- Record last updated2020 · 60% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RG0100X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Gastroenterology Physician providers in California
There are 2,140 gastroenterology physician records in California.
All 2,140 in California → Every provider in Monterey → Gastroenterology Physician nationwide →
The 8 gastroenterology physician records with the nearest ZIP codes
- James Di Sario, M.D.Monterey, CA 939401376553180
- Jeffrey Fiorenza, M.D.Monterey, CA 939401851577605
- Lloyd Garren, M.D.Monterey, CA 939401841200565
- Mary Garren, M.D.Monterey, CA 939401801806567
- Richard Hell, M.D.Monterey, CA 939401114937927
- Steve HuMonterey, CA 939401568880508
- Jan Kamler, MDMonterey, CA 939401093791824
- Toby Katz, M.D.Monterey, CA 939401336159052
Common questions
What is Isabelle Barnard Moonan, M.D.'s NPI number?
Isabelle Barnard Moonan, M.D.'s National Provider Identifier (NPI) is 1568472298, issued on Aug 8, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Isabelle Barnard Moonan, M.D. located?
The NPPES record lists a practice address at 23 Upper Ragsdale Dr, Monterey, CA, 93940. Phone: (831) 375-3577. Providers update this record themselves, so call before visiting.
How can I verify Isabelle Barnard Moonan, M.D.'s license?
NPPES lists California license number A51122, 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 Isabelle Barnard Moonan, M.D. prescribe under Medicare Part D?
In 2024, Isabelle Barnard Moonan, M.D. had 620 Medicare Part D claims for 258 beneficiaries; the average among gastroenterology physician prescribers was 811. Part D covers Medicare prescriptions only.
What is Isabelle Barnard Moonan, M.D.'s MIPS final score?
The 2023 MIPS final score is 83.8 of 100, reported for the practice group. The average among 454,083 clinicians with a measured score was 83.5.
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.