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Internal Medicine Providers in Fontana, CA

Browse 111 Internal Medicine providers listed in NPPES with a practice address in Fontana, California.

111 Healthcare Providers

How Fontana compares with the U.S.

Fontana has 52 clinicians in Internal Medicine per 100,000 residents, 17% higher than the U.S. rate of 44.

That is 111 active clinicians in Internal Medicine with a practice address in Fontana, for a population of 214,169.

The California rate is 45 per 100,000 residents.

What these numbers mean

Clinicians per 100,000 residents compares places of different sizes. We count active clinicians who list a practice address in the area in the federal NPI registry (NPPES) and divide by the number of people who live there, according to the U.S. Census Bureau. The U.S. rate is the same calculation for the whole country.

A higher number does not mean it is easier to get an appointment, that wait times are shorter, or that care is better. It also does not show how many clinicians are accepting new patients or which insurance plans they take. A lower number does not by itself mean there is a shortage.

City counts use the city name in each clinician's practice address. That postal city can cover a larger or smaller area than the city limits the Census Bureau uses for population, and many clinicians list only one address even if they work in several places.

97% of clinicians in Internal Medicine in Fontana listed in the CMS Medicare file (73 of 75) accept Medicare assignment. That is similar to the California share of 96%.

What is Medicare assignment?

A clinician who accepts Medicare assignment agrees to take the Medicare-approved amount as full payment for services that Original Medicare covers. You usually still pay your deductible and coinsurance. This comes from the CMS Doctors and Clinicians file and applies to Original Medicare only. Medicare Advantage plans have their own provider networks. It does not show whether a clinician is taking new patients.

Some clinicians are listed as "may accept assignment," which means they can decide case by case. Clinicians without an assignment flag, or who are not in the CMS file, are not counted as accepting assignment. That does not mean they refuse Medicare. Ask the office before your visit.

15% of clinicians in Internal Medicine in Fontana listed in the CMS Medicare file (11 of 75) have a CMS telehealth indicator, meaning their recent Medicare claims include telehealth services. That is lower than the California share of 38%.

About the telehealth indicator

The telehealth indicator comes from CMS. It marks clinicians whose recent paid Medicare claims include services delivered by telehealth. It means a clinician has provided some services by telehealth, not that every visit can be done online. A clinician without the indicator may still offer telehealth, for example to patients who are not on Medicare. Ask the office which visits can be done by video or phone.

These figures summarize public federal data. They do not measure quality of care, appointment availability, or whether a clinician accepts your insurance or new patients. Registry addresses can be out of date. Please confirm details directly with the office and your plan. This information is not medical advice.

Prepared by T-MedInfo from NPPES, CMS and U.S. Census Bureau data. Questions or corrections: support@true-medinfo.com ยท Methodology

Sources: Clinician counts and practice addresses: NPPES NPI Registry, Centers for Medicare & Medicaid Services (CMS), data as of August 2026. Medicare assignment and telehealth indicators: CMS Doctors and Clinicians National Downloadable File. Population: U.S. Census Bureau, American Community Survey 2020-2024 5-Year Estimates, Table B01003 (Total Population).

Internal Medicine Medicare (PECOS) Enrollment & Ordering Eligibility

Medicare enrollment and order/referring eligibility listed by CMS for Internal Medicine practitioners in Fontana, CA

Source: CMS PECOS
PECOS Enrolled Specialists 89 In Fontana, CA
Part B Lab & Imaging Eligible 89 Diagnostic Referrals
DME Ordering Eligible 92 Durable Medical Equipment
Home Health Agency Referrals 89 HHA Ordering Eligible
Showing 1โ€“20 of 111 providers
With recent CMS data first, then Aโ€“Z

Dr. Danish Abbas , MD

Internal Medicine

Active NPI Status Accepts Medicare Assignment
9961 Sierra Ave Fl Mob26, Fontana, CA 923356720
Phone: 9094272608
NPI Identifier 1104267053
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Dr. Faramarz Alav , MD

Internal Medicine

Active NPI Status Telehealth Services Available
16465 Sierra Lakes Pkwy Ste 200, Fontana, CA 923361242
Phone: 9094292404
NPI Identifier 1508825027
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Dr. Ashley Hao-Ai Alexander , DO

Internal Medicine

Active NPI Status Accepts Medicare Assignment
9961 Sierra Ave, Main Hospital, 5th Floor, Room 5406, Fontana, CA 92335
Phone: 9094275000
NPI Identifier 1568882298
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Syeda Ameena

Internal Medicine

Active NPI Status
7774 Cherry Ave, Fontana, CA 923364014
Phone: 9093551296
NPI Identifier 1972998706
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Dr. Dorcas C. Ang , MD

Internal Medicine

Active NPI Status Accepts Medicare Assignment Telehealth Services Available
9961 Sierra Ave, Fontana, CA 923356720
Phone: 9094273910
NPI Identifier 1508914417
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Dr. Arman Aryai , MD

Internal Medicine

Active NPI Status Accepts Medicare Assignment
9961 Sierra Ave, Fontana, CA 923356720
Phone: 9094273910
NPI Identifier 1851592737
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Dr. Amal Ballat , MD

Internal Medicine

Active NPI Status Accepts Medicare Assignment
9961 Sierra Ave, Fontana, CA 923356720
Phone: 9094273910
NPI Identifier 1063560951
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Dr. Sanjay C. Bhakta , MD

Internal Medicine

Active NPI Status Accepts Medicare Assignment
9961 Sierra Ave, Fontana, CA 923356720
Phone: 9094273910
NPI Identifier 1053469924
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Dr. Christine Bui , DO

Internal Medicine

Active NPI Status Accepts Medicare Assignment
9961 Sierra Ave, Fontana, CA 923356720
Phone: 8887500036
NPI Identifier 1285095752
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Andrew Steven Chen

Internal Medicine

Active NPI Status Accepts Medicare Assignment
14050 Cherry Ave Ste C, Fontana, CA 923378312
Phone: 9098235220
NPI Identifier 1053873646
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Dr. Michael P. Chen , MD

Internal Medicine

Active NPI Status
9961 Sierra Ave, Fontana, CA 923356720
Phone: 9094273910
NPI Identifier 1306913256
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Dr. Philomena J. Cho , MD

Internal Medicine

Active NPI Status Accepts Medicare Assignment
9961 Sierra Ave, Fontana, CA 923356720
Phone: 9094273910
NPI Identifier 1821157421
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Dr. Duane A. Collins , MD

Internal Medicine

Active NPI Status Accepts Medicare Assignment
9961 Sierra Ave, Fontana, CA 923356720
Phone: 9094273910
NPI Identifier 1932276847
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Dr. Jasmit Kaur Dhaliwal , MD

Internal Medicine

Active NPI Status Accepts Medicare Assignment
9961 Sierra Ave, Fontana, CA 923356720
Phone: 9094273910
NPI Identifier 1235287186
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Dr. Pooneh Esfahani , DO

Internal Medicine

Active NPI Status Accepts Medicare Assignment Telehealth Services Available
9961 Sierra Ave, Fontana, CA 923356720
Phone: 9094273910
NPI Identifier 1821146804
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Dr. Arash Faghieh , MD

Internal Medicine

Active NPI Status Accepts Medicare Assignment
9961 Sierra Ave, Fontana, CA 923356720
Phone: 9094273910
NPI Identifier 1598813545
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Dr. Xu Long He , DO

Internal Medicine

Active NPI Status Accepts Medicare Assignment Telehealth Services Available
16465 Sierra Lakes Pkwy Ste 115, Fontana, CA 923361242
Phone: 9098238000
NPI Identifier 1568773448
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Dr. Edmond C. Hui , MD

Internal Medicine

Active NPI Status
9961 Sierra Ave, Fontana, CA 923356720
Phone: 9094273910
NPI Identifier 1043379647
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Dr. Cliff J. Hwang , MD

Internal Medicine

Active NPI Status
9961 Sierra Ave, Fontana, CA 923356720
Phone: 9094273910
NPI Identifier 1336216266
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Dr. Wei Chan Hwang , MD

Internal Medicine

Active NPI Status Accepts Medicare Assignment
9961 Sierra Ave, Medical Staff Office/ Kaiser Permanente Fontana, Fontana, CA 923356720
Phone: 9094272673
NPI Identifier 1104976141
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Frequently Asked Questions about Internal Medicine in Fontana

How do I check a Internal Medicine practitioner's license?

Each practitioner profile shows the NUCC taxonomy code and any state license number the practitioner reported to NPPES, plus a link to the California licensing board lookup. NPPES entries are self-reported; current license status is published only by the state board.

Why is a practitioner missing from this list?

This list shows NPI records that are active in NPPES. A deactivated NPI keeps its profile with the deactivation date and practice history; find it with the site search by name or NPI number.