Mariel Bailey, MD
Internal Medicine Physician · Walnut Creek, CA
Mariel Bailey, MD is an internal medicine physician with a practice address in Walnut Creek, California, and NPI 1710415435, issued on May 25, 2017. Check the license (California A195655, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Mariel Bailey
- Credential
- MD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- A195655 CA
Self-reported in NPPES; status is on the state search - Practice location
- 1425 S Main St, Walnut Creek, CA 94596
- Phone
- (925) 295-4000
- Enumerated
- May 25, 2017
- Record last updated
- Aug 21, 2024
- Medicare enrollment
- Enrolled (PECOS I20240924000958); accepts Medicare assignment
- Medical or professional school
- University Of California, Geffen School Of Medicine, 2017
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Also registered at 1425 S Main St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Eric AaserudeEmergency Medicine Physician1811491194
- Derek Abbassi, MDObstetrics & Gynecology Physician1841364155
- Peter Ackerman, MDEmergency Medicine Physician1427435023
- Aaron Mark Acosta, DOEmergency Medicine Physician1538789987
- Basil Adad, MDOtolaryngology Physician1487732574
- Derek Ailes, M.D.Emergency Medical Services (Emergency Medicine) Physician1992001804
Verify Mariel Bailey in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A195655Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
96% fewer Medicare Part D claims than the average internal medicine physician in 2024
116 Medicare Part D claims for 48 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 25% of claims.
Most prescribed
- Omeprazole20 claims
- Mesalamine12 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: $84.00
1 payment: education; the largest payer was Janssen Biotech, Inc. The 50,334 providers of this specialty with any payment received $1,303.06 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
- Permanente Medical Group IncAntioch, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Mariel Bailey among 17,696 internal medicine physician records in California
Mariel Bailey, MD is one of 17,696 internal medicine physician records with a practice address in California. 79% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2017, is newer than 81% of them.
- NPI issued2017 · 81% of these records are older, 16% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated2017 · median 2004 among the 11,065 with a school on file
- Record last updated2024 · 61% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207R00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
183 internal medicine physician records list a practice address in Walnut Creek
They are 183 of the 6,170 NPPES records with a practice address in Walnut Creek, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in Walnut Creek → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Anthony Arroyo, MDWalnut Creek, CA 945961376621458
- Sheila Bhatia, MDWalnut Creek, CA 945961225135379
- Amrita Dhaliwal, MDWalnut Creek, CA 945961164500740
- Nellia Karakozova, MDWalnut Creek, CA 945961659459154
- Joseph Long, MDWalnut Creek, CA 945961225116379
- Roxanne McDaniel, MDWalnut Creek, CA 945961457439937
- Huu Nguyen, D.O.Walnut Creek, CA 945961811966492
- Jeff Ortiz, MDWalnut Creek, CA 945961891873964
Common questions
What is Mariel Bailey, MD's NPI number?
Mariel Bailey, MD's National Provider Identifier (NPI) is 1710415435, issued on May 25, 2017. An NPI identifies a provider in billing; it is not a license.
Where is Mariel Bailey, MD located?
The NPPES record lists a practice address at 1425 S Main St, Walnut Creek, CA, 94596. Phone: (925) 295-4000. Providers update this record themselves, so call before visiting.
How can I verify Mariel Bailey, MD's license?
NPPES lists California license number A195655, 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 Mariel Bailey, MD prescribe under Medicare Part D?
In 2024, Mariel Bailey, MD had 116 Medicare Part D claims for 48 beneficiaries; the average among internal medicine physician prescribers was 3,176. 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.