NPPES file of Aug 9, 2026

Jay Donald Grassell, MD

Hospitalist Physician · Marysville, CA

Jay Donald Grassell, MD is a hospitalist physician with a practice address in Marysville, California, and NPI 1821029687, issued on Jul 6, 2006. Check the license (California G63050, 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 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1821029687
Name
Jay Donald Grassell
Credential
MD
Primary taxonomy
Hospitalist Physician 208M00000X
License numbers
G63050 CA
G063050 CA
Self-reported in NPPES; status is on the state search
Practice location
414 G Street, Marysville, CA 95901
Phone
(530) 741-1642
Enumerated
Jul 6, 2006
Record last updated
Nov 19, 2021 (not updated in 5 years: call before relying on the address or phone)
Fax
(530) 741-2056
Medicare enrollment
Enrolled (PECOS I20061005000563); accepts Medicare assignment
Medical or professional school
Medical College Of Wisconsin, 1981
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). Enrollment, assignment, school and telehealth: CMS Doctors and Clinicians file, Aug 2026. A record is not a license: verify it with the state board.
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Verify Jay Donald Grassell in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersMedical Board of California
    Search for license G63050
    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.

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Bills Medicare through one group practice

  1. Galen Inpatient Physicians PCHanford, CA

Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).

Jay Donald Grassell among 3,099 hospitalist physician records in California

Jay Donald Grassell, MD is one of 3,099 hospitalist physician records with a practice address in California. 90% 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 2% of them.

  • NPI issued2006 · 2% of these records are older, 73% newer
  • In a Medicare fileYes · 90% of these records are
  • In the CMS Doctors and Clinicians fileYes · 81% of these records are
  • Graduated1981 · median 2010 among the 2,505 with a school on file
  • Record last updated2021 · 49% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 208M00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

Hospitalist Physician providers in California

There are 3,099 hospitalist physician records in California.

The 8 hospitalist physician records with the nearest ZIP codes

  1. Douglas Fujii, D.O.Marysville, CA 959011053471490
  2. Amul Garg, M.D,Marysville, CA 959011457343543
  3. Gagandeep Kaur, M.D.Marysville, CA 959011780624130
  4. Piyush Kumar, MDMarysville, CA 959011720234024
  5. Michael Neal, D.O.Marysville, CA 959011932137460
  6. Harkamal Singh, M.D.Marysville, CA 959011831342534
  7. Francisco Alvarez, M.D.Chico, CA 959261588690648
  8. Attila Kasza, M.D.Chico, CA 959261952340937

Common questions

What is Jay Donald Grassell, MD's NPI number?

Jay Donald Grassell, MD's National Provider Identifier (NPI) is 1821029687, issued on Jul 6, 2006. An NPI identifies a provider in billing; it is not a license.

Where is Jay Donald Grassell, MD located?

The NPPES record lists a practice address at 414 G Street, Marysville, CA, 95901. Phone: (530) 741-1642. Providers update this record themselves, so call before visiting.

How can I verify Jay Donald Grassell, MD's license?

NPPES lists California license number G63050, 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.

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.