Donald Gratton Downs, MD.
Family Medicine Physician · Simi Valley, CA
Donald Gratton Downs, MD. is a family medicine physician with a practice address in Simi Valley, California, and NPI 1568451979, issued on Oct 18, 2005. Check the license (California G61850, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Donald Gratton Downs
- Credential
- MD.
- Primary taxonomy
- Family Medicine Physician 207Q00000X
- License number
- G61850 CA
Self-reported in NPPES; status is on the state search - Practice location
- 2655 1St St, Simi Valley, CA 93065
- Phone
- (805) 206-2000
- Enumerated
- Oct 18, 2005
- Record last updated
- Apr 3, 2014 (not updated in 12 years: call before relying on the address or phone)
- Fax
- (805) 577-1270
- Medicaid ID
- 00G618500 CA
- Medicare enrollment
- Enrolled (PECOS I20051209000774); accepts Medicare assignment
- Medical or professional school
- University Of California, San Diego School Of Medicine, 1986
- Entity
- Type 1 · individual
8 nearest family medicine physician records → All 17,133 in California → Look up another NPI →
Also registered at 2655 1St St
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Jutharat Pattanachinda, M.D.Pediatrics Physician1720077423
- Luis ReyesElectroneurodiagnostic Specialist/Technologist1073991527
Verify Donald Gratton Downs in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license G61850Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
9% more Medicare Part D claims than the average family medicine physician in 2024
3,849 Medicare Part D claims for 268 beneficiaries, against an average of 3,544 among the 117,163 providers of this specialty who prescribed in Part D. Brand-name drugs were 11% of claims. 174 claims were for opioids.
Most prescribed
- Atorvastatin Calcium314 claims
- Losartan Potassium196 claims
- Lisinopril138 claims
- Amlodipine Besylate134 claims
- Levothyroxine Sodium127 claims
- Omeprazole99 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
- Providence Facey Medical FoundationPorter Ranch, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Donald Gratton Downs among 17,133 family medicine physician records in California
Donald Gratton Downs, MD. is one of 17,133 family medicine physician records with a practice address in California. 81% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2005, is newer than 0% of them.
- NPI issued2005 · 0% of these records are older, 94% newer
- In a Medicare fileYes · 81% of these records are
- In the CMS Doctors and Clinicians fileYes · 62% of these records are
- Graduated1986 · median 2005 among the 10,652 with a school on file
- Record last updated2014 · 58% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207Q00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
60 family medicine physician records list a practice address in Simi Valley
They are 60 of the 1,397 NPPES records with a practice address in Simi Valley, and 17,133 family medicine physician records in California.
All 17,133 in California → Every provider in Simi Valley → Family Medicine Physician nationwide →
The 8 family medicine physician records with the nearest ZIP codes
- Ingrid Antall, MDSimi Valley, CA 930651629061700
- George Carbone, M.D.Simi Valley, CA 930651437124849
- Jerry Davidson, M.D.Simi Valley, CA 930651922073998
- Harry Drummond, MDSimi Valley, CA 930651164416517
- Daniel Ghiyam, MDSimi Valley, CA 930651750378188
- Shayla Kasel, M.D.Simi Valley, CA 930651649241837
- Jonathan Kurohara, M.DSimi Valley, CA 930651427023407
- Masahiro Kushigemachi, M.D.Simi Valley, CA 930651386617058
Common questions
What is Donald Gratton Downs, MD.'s NPI number?
Donald Gratton Downs, MD.'s National Provider Identifier (NPI) is 1568451979, issued on Oct 18, 2005. An NPI identifies a provider in billing; it is not a license.
Where is Donald Gratton Downs, MD. located?
The NPPES record lists a practice address at 2655 1St St, Simi Valley, CA, 93065. Phone: (805) 206-2000. Providers update this record themselves, so call before visiting.
How can I verify Donald Gratton Downs, MD.'s license?
NPPES lists California license number G61850, 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 Donald Gratton Downs, MD. prescribe under Medicare Part D?
In 2024, Donald Gratton Downs, MD. had 3,849 Medicare Part D claims for 268 beneficiaries; the average among family medicine physician prescribers was 3,544. 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.