DENISE LAM MAH FNP-BC
NPI 1083114508
Nurse Practitioner - Family in Fontana, CA
About Denise Lam Mah Fnp-bc NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DENISE LAM MAH FNP-BC (NPI 1083114508) is an individual family provider in Fontana, California, licensed in California (95008068) and active in the NPI registry since February 2018. She is enrolled in Medicare PECOS, maintains a secondary practice location in Duarte, and is a graduate of Other (2017).
NPPES Registry Identity
Specialties & Licenses 2
Secondary Practice Location 1
Group Practice 1
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare and accepts Medicare assignment
Denise Lam Mah Fnp-bc is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.
Medicare Billing Reassignments
2Medicare enrollment records show Denise Mah reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Duarte, CA 91010
- Reassigned Medicare billing, California enrollment
- 1,335 clinicians in this Medicare group
Los Angeles, CA 90034
- Reassigned Medicare billing, California enrollment
- Medicare enrollment name: Minghsun Liu MD PC
- 95 clinicians in this Medicare group
Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
Areas of Expertise CMS Part B claims 5
Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.
Physician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 92335 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Medicare Quality Performance CMS QPP · MIPS
Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.
Referred Medical Equipment & Supplies CMS DME claims 7
Durable medical equipment, devices and supplies this provider ordered from DME suppliers for patients, from Medicare fee-for-service claims.
Other Providers at the Same Location NPPES 20
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
FONTANA, CA 92335
Frequently Asked Questions NPPES & CMS
Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.
What is Denise Mah's NPI number?
The NPI number for Denise Mah is 1083114508. It was assigned to this individual provider in the NPPES registry on February 21, 2018.
Where is Denise Mah located?
Denise Mah practices at 9961 Sierra Ave, Fontana, CA 92335. The listed phone number is (909) 396-7812.
What is Denise Mah's specialty?
The primary specialty registered for this NPI is Nurse Practitioner, specializing in Family, with taxonomy code 363LF0000X.
Is Denise Mah enrolled in Medicare?
Yes. Denise Mah is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.
Which organizations bill Medicare for Denise Mah's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Denise Mah reassigns Medicare benefits to 2 organizations: City Of Hope Medical Foundation (Duarte, CA) and Minghsun Liu, M.D., PC (Los Angeles, CA). Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Denise Mah's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
When was this NPI record last updated?
The NPPES record for Denise Mah was last updated on May 24, 2021. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 5 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.
# Denise Lam Mah, FNP-BC · NPI 1083114508
Family physician in Fontana, California. Individual provider, active in the CMS NPPES registry since February 21, 2018.
## Identity
- **NPI:** 1083114508 (Entity type: Individual)
- **Enumerated:** February 21, 2018
- **Primary specialty:** Nurse Practitioner - Family · taxonomy 363LF0000X
- **State license:** 95008068 (California)
- **Sole proprietor:** Yes
## Practice location
- **Address:** 9961 SIERRA AVE, Fontana, CA 92335-6720
- **Phone:** (909) 396-7812
## Medicare
- **Medicare:** Enrolled (PECOS); accepts Medicare assignment
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** 2 organizations under Medicare reassignment (form CMS-855R): City Of Hope Medical Foundation (NPI 1871886366, Duarte, CA); Minghsun Liu, M.D., PC (NPI 1518309368, Los Angeles, CA) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 2017
## Record status
- **NPPES last updated:** May 24, 2021
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Source: [NPI Profile](https://npiprofile.com/npi/1083114508) · Data from the CMS NPPES public registry.