Registry data as of Aug 27, 2026

Jason Massa, D.O.

Neurology Physician · Walnut Creek, CA

Jason Massa, D.O. is a neurology physician with a practice address in Walnut Creek, California, and NPI 1841636156, issued on May 14, 2013. Check the license (California 20A13615, 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
1841636156
Name
Jason Massa
Credential
D.O.
Primary taxonomy
Neurology Physician 2084N0400X
License number
20A13615 CA
Self-reported in NPPES; status is on the state search
Practice location
675 Ygnacio Valley RD, Walnut Creek, CA 94596
Phone
(925) 938-5252
Enumerated
May 14, 2013
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 675 Ygnacio Valley RD

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

  1. Thomas Callan, ODOptometrist1043348394
  2. Stephanie Chan, ODOptometrist1689635542
  3. Ming Fang, MDGastroenterology Physician1366520199
  4. Jonathan Geleris, D.D.S.General Practice Dentistry1043686850
  5. Nicholas Hyde, MDPhlebology Physician1255511788
  6. Maridez Jenkins, F.N.P.Family Nurse Practitioner1245570266

Verify Jason Massa in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license 20A13615
    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 →

31% fewer Medicare Part D claims than the average neurology physician in 2024

936 Medicare Part D claims for 134 beneficiaries, against an average of 1,356 among the 13,714 providers of this specialty who prescribed in Part D. Brand-name drugs were 14% of claims.

  1. Jason Massa936
  2. Specialty average1,356

Most prescribed

  1. Carbidopa-Levodopa301 claims
  2. Carbidopa-Levodopa Er107 claims
  3. Rytary85 claims
  4. Amantadine55 claims
  5. Donepezil Hcl53 claims
  6. Citalopram Hbr39 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 Medicare quality score for 2023: 100 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.

  1. Qualityout of 100 · 30% of the final score100.0
  2. Costout of 100 · 30%
  3. Promoting interoperabilityout of 100 · 25%100.0
  4. Improvement activities40 of 40 points · 15%100.0

Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).

Industry payments in 2024: $631.34

24 payments, mostly food and beverage; the largest payer was Neurocrine Biosciences, Inc.. The 9,995 providers of this specialty with any payment received $8,603.82 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.

  1. Jason Massa$631.34
  2. Specialty average$8,603.82

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

One hospital or facility affiliation

  1. East Bay Neurology IncSan Ramon, CA

Source: CMS Doctors and Clinicians affiliations; Hospital General Information (Care Compare) (data.cms.gov). Star ratings are CMS hospital ratings, not ratings of this provider.

Neurology Physician providers in California

There are 2,160 neurology physician records in California.

Other neurology physician records in California

  1. Venkat Raghav Aachi, MDThousand Oaks, CA1740640051
  2. John Aalbers, M.D.San Diego, CA1942262431
  3. Puya Abbassi, D.O.San Jose, CA1831695428
  4. Ahmed Abdelhak, MB CHBSan Francisco, CA1053013748
  5. Hadi Abou El Hassan, MDLos Angeles, CA1053995720
  6. John Paul Aboubechara, MD, PHDPalo Alto, CA1205461803
  7. Justin Abraham, M.D., M.B.A.Santa Barbara, CA1225322522
  8. Scott Abramson, M.D.San Leandro, CA1891873667
  9. Valerie Acevedo, D.O.Newport Beach, CA1043258502
  10. Saviour Achilike, MDTracy, CA1033506688

Common questions

What is Jason Massa, D.O.'s NPI number?

Jason Massa, D.O.'s National Provider Identifier (NPI) is 1841636156, issued on May 14, 2013. An NPI identifies a provider in billing; it is not a license.

Where is Jason Massa, D.O. located?

The NPPES record lists a practice address at 675 Ygnacio Valley RD, Walnut Creek, CA, 94596. Phone: (925) 938-5252. Providers update this record themselves, so call before visiting.

How can I verify Jason Massa, D.O.'s license?

NPPES lists California license number 20A13615, 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 Jason Massa, D.O. prescribe under Medicare Part D?

In 2024, Jason Massa, D.O. had 936 Medicare Part D claims for 134 beneficiaries; the average among neurology physician prescribers was 1,356. Part D covers Medicare prescriptions only.

What is Jason Massa, D.O.'s Medicare quality score?

The 2023 MIPS final score is 100 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), 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.