Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.
NPIDirectory

Dr. Mary Stillwell Hatcher-Dewey, MD

Individual provider Emergency Medicine Physician · NPI 1407157522

Dr. Mary Stillwell Hatcher-Dewey, MD practises Emergency Medicine in San Leandro, California. Graduated from Yale University School of Medicine in 2008, 18 years ago. Practices with Permanente Medical Group Inc, a 10,941-clinician group and accepts Medicare assignment. Licensed in California.

Years since qualifying
18
Trained at
Yale University School of Medicine
Licensed in
CA
In the registry since
2010
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

See every abbreviation used in this directory →

Claim this listing Report a problem Suggest an edit

Practice location Address checks out

2500 Merced St
San Leandro, CA 94577-4201
Phone: (510) 454-1000
Show map & directions

Directions in Google Maps · Apple Maps · OpenStreetMap

Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Emergency Medicine Physician (primary) Taxonomy 207P00000X · Licence A112113 (CA)

Record details

NPI number1407157522
Entity typeIndividual (Type 1)
GenderFemale
Credentials MD
Sole proprietorYes
NPI enumeratedNovember 5, 2010
Last updated in NPPESFebruary 11, 2022

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyEMERGENCY MEDICINE
Medical schoolYALE UNIVERSITY SCHOOL OF MEDICINE
Graduated 2008 (18 years in practice)
Group practice Permanente Medical Group Inc — 10941 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations2 on file with Medicare

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients20
Services billed 20 a service is one billed item, such as a visit, a test or a procedure
Average patient age63

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician.

Colleagues at Permanente Medical Group Inc

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 10941 clinicians in the practice; 12 are shown here.

Other providers in San Leandro