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

Denise Lam Mah, FNP-BC

Individual provider Enterostomal Therapy Registered Nurse · NPI 1083114508

Denise Lam Mah, FNP-BC is a Nurse Practitioner in Fontana, California. Qualified in 2017, 9 years ago. Practices with City of Hope Medical Foundation, a 959-clinician group, works from 2 locations and accepts Medicare assignment. Licensed in California.

Years since qualifying
9
Licensed in
CA
In the registry since
2018
Specialties on file
2
What do these letters mean?
FNP-BC — Family Nurse Practitioner, Board Certified
A family nurse practitioner certified by the ANCC.

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Practice location Address checks out

9961 Sierra Ave
Fontana, CA 92335-6720
Phone: (909) 396-7812
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Additional practice locations (1)

  • 1500 Duarte Rd, Duarte, CA 91010-3012 — (626) 256-4673

Specialties & licences

Family Nurse Practitioner (primary) Taxonomy 363LF0000X · Licence 95008068 (CA)
Enterostomal Therapy Registered Nurse Taxonomy 163WE0900X · Licence 95008068 (CA)

Record details

NPI number1083114508
Entity typeIndividual (Type 1)
GenderFemale
Credentials FNP-BC
Sole proprietorYes
NPI enumeratedFebruary 21, 2018
Last updated in NPPESMay 24, 2021
Certification dateMay 24, 2021

Medicare enrollment

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

Medicare specialtyNURSE PRACTITIONER
Medical schoolOTHER
Graduated 2017 (9 years in practice)
Group practice City Of Hope Medical Foundation — 959 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations3 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 patients66
Services billed 510 a service is one billed item, such as a visit, a test or a procedure
Average patient age73

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.

Payments from drug and device companies, 2025

Drug and device makers are required by federal law (the Physician Payments Sunshine Act) to report what they pay or give to clinicians, and CMS publishes the reports as Open Payments. This is the 2025 program year. A report is a record of a payment, not an allegation of anything, and many are small items such as meals. Only general payments are listed here; research payments and ownership or investment interests are reported separately by CMS and are not shown.

Food and Beverage $152 6 payments · a meal or drink at a meeting or visit, not a fee

Each amount is the sum of what companies reported for that kind of payment in 2025, rounded to the dollar. Not all of it is income to the clinician: a meal is not a fee, a charitable contribution goes to a charity, and a royalty or an acquisition payment is not a salary.

Check a report, or dispute one, at the source in CMS’s own tool, Open Payments. Corrections go through CMS’s dispute process. This site removes a home address on request and asks for no proof, because that is privacy; it will not remove an accurate payment report on request, because that is a statutory public disclosure.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician.

Affiliated with 1 hospital, which CMS identifies by certification number only.

Colleagues at City of Hope Medical Foundation

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 959 clinicians in the practice; 12 are shown here.