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Internal Medicine Providers in Castro Valley, CA

Browse 24 Internal Medicine providers listed in NPPES with a practice address in Castro Valley, California.

24 Healthcare Providers

How Castro Valley compares with the U.S.

Castro Valley has 37 clinicians in Internal Medicine per 100,000 residents, 17% lower than the U.S. rate of 44.

That is 24 active clinicians in Internal Medicine with a practice address in Castro Valley, for a population of 65,001.

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.

100% of clinicians in Internal Medicine in Castro Valley listed in the CMS Medicare file (15 of 15) 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.

33% of clinicians in Internal Medicine in Castro Valley listed in the CMS Medicare file (5 of 15) have a CMS telehealth indicator, meaning their recent Medicare claims include telehealth services. That is similar to 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 Castro Valley, CA

Source: CMS PECOS
PECOS Enrolled Specialists 17 In Castro Valley, CA
Part B Lab & Imaging Eligible 17 Diagnostic Referrals
DME Ordering Eligible 17 Durable Medical Equipment
Home Health Agency Referrals 17 HHA Ordering Eligible
Showing 1โ€“20 of 24 providers
With recent CMS data first, then Aโ€“Z

Dr. Nabil Karim Abudayeh , MD

Internal Medicine

Active NPI Status Accepts Medicare Assignment Telehealth Services Available
20700 Lake Chabot Road, Ste 107, Castro Valley, CA 945465402
Phone: 5108866878
NPI Identifier 1699724484
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Dr. Monica Bhargava , MD

Internal Medicine

Active NPI Status Accepts Medicare Assignment
20103 Lake Chabot Rd, Castro Valley, CA 945465305
Phone: 5108895082
NPI Identifier 1619900347
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Dr. Shiven Chaudhry , MD

Internal Medicine

Active NPI Status Accepts Medicare Assignment
20642 John Dr, Castro Valley, CA 945465103
Phone: 5107855000
NPI Identifier 1528594801
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Active NPI Status Accepts Medicare Assignment
20103 Lake Chabot Rd, Castro Valley, CA 945465305
Phone: 5108895082
NPI Identifier 1548557077
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Dr. Diana Hess , MD

Internal Medicine

Active NPI Status Accepts Medicare Assignment Telehealth Services Available
20101 Lake Chabot Rd Fl 3, Castro Valley, CA 945465305
Phone: 5108863400
NPI Identifier 1295296275
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Dr. Richard Ho , MD

Internal Medicine

Active NPI Status Accepts Medicare Assignment Telehealth Services Available
20126 Stanton Ave Ste 201, Castro Valley, CA 94546
Phone: 5105812559
NPI Identifier 1548283005
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Dr. Nidhi Johri , MD

Internal Medicine

Active NPI Status Accepts Medicare Assignment Telehealth Services Available
20642 John Dr, Castro Valley, CA 945465103
Phone: 5107855000
NPI Identifier 1285811489
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Donald Richard Knotts , MEDICAL DOCTOR

Internal Medicine

Active NPI Status
20130 Lake Chabot Rd, Suite 309, Castro Valley, CA 945465340
Phone: 5108863701
NPI Identifier 1790858611
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Dr. Saima Mahmood , MD

Internal Medicine

Active NPI Status Accepts Medicare Assignment
5618 Gold Creek Dr, Castro Valley, CA 945525440
Phone: 2564739788
NPI Identifier 1477555811
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Dr. Nazia Mir , MD

Internal Medicine

Active NPI Status Accepts Medicare Assignment
20101 Lake Chabot Rd, Castro Valley, CA 945465305
Phone: 5107273256
NPI Identifier 1598128415
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Dr. Khoa Dang Nguyen , MD

Internal Medicine

Active NPI Status
20103 Lake Chabot Rd, Castro Valley, CA 945465305
Phone: 5107273256
NPI Identifier 1386962421
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Dr. Mridula Rewal , MD

Internal Medicine

Active NPI Status Accepts Medicare Assignment
20103 Lake Chabot Rd, Castro Valley, CA 94546
Phone: 5107273256
NPI Identifier 1831526300
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Rahel Teferi Ruiz

Internal Medicine

Active NPI Status Accepts Medicare Assignment
18675 Buren Pl, Castro Valley, CA 945525281
Phone: 5108812192
NPI Identifier 1821089129
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Dr. Omar Faisal Saleem , MD

Internal Medicine

Active NPI Status Accepts Medicare Assignment
20103 Lake Chabot Rd, Castro Valley, CA 945465305
Phone: 5107273256
NPI Identifier 1053844183
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Dr. Petr Utrata , MD

Internal Medicine

Active NPI Status
19100 Crest Ave Apt 24, Castro Valley, CA 945462863
Phone: 6502888344
NPI Identifier 1376624742
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Dr. Stefani Wedl , MD

Internal Medicine

Active NPI Status Accepts Medicare Assignment
20103 Lake Chabot Rd, Castro Valley, CA 945465305
Phone: 5108895082
NPI Identifier 1073538518
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Dr. Ling Xu , MD

Internal Medicine

Active NPI Status Accepts Medicare Assignment Telehealth Services Available
20642 John Dr, Castro Valley, CA 945465103
Phone: 5107855000
NPI Identifier 1073684429
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Dr. Helen Woohee Yang , MD

Internal Medicine

Active NPI Status Accepts Medicare Assignment
20642 John Dr, Castro Valley, CA 945465103
Phone: 5108062100
NPI Identifier 1003270877
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Dr. Wing Chin , MD

Internal Medicine

Active NPI Status
20055 Lake Chabot Rd, #300, Castro Valley, CA 945465331
Phone: 5108862311
NPI Identifier 1124052576
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Dr. Kathryn Hodge , MD

Internal Medicine

Active NPI Status
20103 Lake Chabot Rd, Castro Valley, CA 945465305
Phone: 5108895082
NPI Identifier 1194741256
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Frequently Asked Questions about Internal Medicine in Castro Valley

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.