Mark I. Grijnsztein, M.D.
Allergy & Immunology Physician · Elk Grove, CA
Mark I. Grijnsztein, M.D. is an allergy & immunology physician with a practice address in Elk Grove, California, and NPI 1164580866, issued on Dec 5, 2006. Check the license (California A96813, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Mark I. Grijnsztein
- Credential
- M.D.
- Primary taxonomy
- Allergy & Immunology Physician 207K00000X
- License number
- A96813 CA
Self-reported in NPPES; status is on the state search - Practice location
- 8170 Laguna Blvd, Elk Grove, CA 95758
- Phone
- (916) 478-6555
- Enumerated
- Dec 5, 2006
- Record last updated
- Jul 29, 2015 (not updated in 11 years: call before relying on the address or phone)
- Medicare enrollment
- Enrolled (PECOS I20070111000313); accepts Medicare assignment
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest allergy & immunology physician records → All 444 in California → Look up another NPI →
Also registered at 8170 Laguna Blvd
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Sina Ali, NURSE PRACTIONERPrimary Care Nurse Practitioner1639859077
- Thomas Atkins, MDFamily Medicine Physician1093728776
- Morteza Beheshtian, DDSGeneral Practice Dentistry1033267422
- Kendra Blanchette, RD, CSR, CDCESRegistered Dietitian1891501805
Verify Mark I. Grijnsztein in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A96813Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
11% more Medicare Part D claims than the average allergy & immunology physician in 2024
819 Medicare Part D claims for 181 beneficiaries, against an average of 741 among the 2,899 providers of this specialty who prescribed in Part D. Brand-name drugs were 45% of claims.
Most prescribed
- Ipratropium Bromide126 claims
- Trelegy Ellipta70 claims
- Dupixent Syringe67 claims
- Azelastine Hcl51 claims
- Fluticasone Propionate46 claims
- Albuterol Sulfate Hfa43 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.
Bills Medicare through one group practice
- Sutter Valley Medical FoundationSacramento, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Mark I. Grijnsztein among 444 allergy & immunology physician records in California
Mark I. Grijnsztein, M.D. is one of 444 allergy & immunology 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 2006, is newer than 7% of them.
- NPI issued2006 · 7% of these records are older, 53% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated1998 · median 2004 among the 281 with a school on file
- Record last updated2015 · 62% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207K00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Allergy & Immunology Physician providers in California
There are 444 allergy & immunology physician records in California.
All 444 in California → Every provider in Elk Grove → Allergy & Immunology Physician nationwide →
The 8 allergy & immunology physician records with the nearest ZIP codes
- Ali Amirzadeh, M.D.Sacramento, CA 958161083748685
- Neil Parikh, M.D.Sacramento, CA 958161952531030
- Vinay Goswamy, MDSacramento, CA 958171356792022
- Fatema Mollah, MDSacramento, CA 958171346803269
- Meghan Garcia, M.D.Sacramento, CA 958191891131447
- Teresa Neeno, MDSacramento, CA 958191366553273
- Angelina Crans Yoon, MDWoodland, CA 956951336419290
- Rajan Merchant, M.D.Woodland, CA 956951396773552
Common questions
What is Mark I. Grijnsztein, M.D.'s NPI number?
Mark I. Grijnsztein, M.D.'s National Provider Identifier (NPI) is 1164580866, issued on Dec 5, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Mark I. Grijnsztein, M.D. located?
The NPPES record lists a practice address at 8170 Laguna Blvd, Elk Grove, CA, 95758. Phone: (916) 478-6555. Providers update this record themselves, so call before visiting.
How can I verify Mark I. Grijnsztein, M.D.'s license?
NPPES lists California license number A96813, 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 I. Grijnsztein, M.D. prescribe under Medicare Part D?
In 2024, Mark I. Grijnsztein, M.D. had 819 Medicare Part D claims for 181 beneficiaries; the average among allergy & immunology physician prescribers was 741. 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.