DR. MITCHELL SIY DNP
NPI 1437829058
Nurse Practitioner in Anaheim, CA

Q: What is Mitchell Siy's NPI number?

The NPI number for Mitchell Siy is 1437829058. It was assigned to this individual provider in the NPPES registry on September 15, 2021.

Q: What is Mitchell Siy's specialty?

The primary specialty registered for this NPI is Nurse Practitioner with taxonomy code 363L00000X.

Q: When was this NPI record last updated?

The NPPES record for Mitchell Siy was last updated on November 3, 2021. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 4 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.

Active since September 15, 2021PECOS Enrolled

1111 W LA PALMA AVE, ANAHEIM, CA 92801(714) 774-1450 Get Directions Write a Review

NPPES record last updated: November 3, 2021. Verified against the NPPES registry weekly; last sync: October 18, 2026.

Record update history: Nov 3, 2021, Sep 15, 2021 (2 updates tracked since 2021).

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About Dr. Mitchell Siy Dnp NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

DR. MITCHELL SIY DNP (NPI 1437829058) is an individual nurse practitioner in Anaheim, California, licensed in California (95018377) and active in the NPI registry since September 2021. He is enrolled in Medicare PECOS.

NPPES Registry Identity

NPI1437829058

Entity TypeIndividualMale

Primary Taxonomy363L00000X

Provider Legal NameDR. MITCHELL SIYCredential: DNP

Location Address1111 W LA PALMA AVEAnaheim, CA 92801-2804

Mailing Address5998 Alcala ParkSan Diego, CA 92110-8001

Phone(714) 774-1450

Sole ProprietorYes

Enumeration DateSeptember 15, 2021

Last NPPES UpdateNovember 3, 20212 updates tracked since enumeration

NPPES CertifiedNovember 3, 2021

✔ NPI 1437829058 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyNurse PractitionerPhysician Assistants & Advanced Practice Nursing Providers

Taxonomy Code363L00000X

License✔ Licensed in CA · 95018377

Definition

(1) A registered nurse provider with a graduate degree in nursing prepared for advanced practice involving independent and interdependent decision making and direct accountability for clinical judgment across the health care continuum or in a certified specialty. (2) A registered nurse who has completed additional training beyond basic nursing education and who provides primary health care services in accordance with state nurse practice laws or statutes. Tasks performed by nurse practitioners vary with practice requirements mandated by geographic, political, economic, and social factors. Nurse practitioner specialists include, but are not limited to, family nurse practitioners, gerontological nurse practitioners, pediatric nurse practitioners, obstetric-gynecologic nurse practitioners, and school nurse practitioners.

Also ListedRegistered NurseTaxonomy 163W00000X · License 95026363 (CA)

1111 W LA PALMA AVE, Anaheim, CA 92801

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Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Dr. Mitchell Siy Dnp is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Medicare Billing Reassignments

Medicare enrollment records show Mitchell Siy reassigns Medicare billing to 3 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Cep America - California

1.9 mi

Emergency Medicine

1025 S ANAHEIM BLVD
Anaheim, CA 92805

Reassigned Medicare billing, California enrollment
1,204 clinicians in this Medicare group

NPI 1982078150 (714) 533-6220

Gem Medical Group Corporation

9.1 mi

Emergency Medicine

9080 COLIMA RD
Whittier, CA 90605

Reassigned Medicare billing, California enrollment
80 clinicians in this Medicare group

NPI 1689364721 (877) 346-2211

Can Emergency Physicians Medical Group Inc

9.2 mi

Emergency Medicine

14662 NEWPORT AVE
Tustin, CA 92780

Reassigned Medicare billing, California enrollment
121 clinicians in this Medicare group

NPI 1386018356 (714) 619-7700

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 2

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.

Emergency department visit with moderate level of medical decision making 99284

An emergency department visit for a high-severity issue means you're experiencing a serious health problem that needs immediate attention. This could be a severe injury, serious illness, or life-threatening condition. Medical professionals will provide urgent care to stabilize your condition.

26 services18 patients

Emergency department visit with high level of medical decision making 99285

An emergency department visit for severe conditions is when you urgently seek medical help due to serious health issues. These could be severe injuries, breathing problems, unbearable pain, or sudden severe illness. Doctors and nurses will provide immediate care to stabilize your condition.

12 services12 patients

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 92801 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient

$96.36 typical visit price

range $62.96 – $187.60

Typical copayment $24.09 (range $15.74 – $46.90)

Most-billed visit code 99203

Established Patient

$109.96 typical visit price

range $20.84 – $153.61

Typical copayment $27.49 (range $5.21 – $38.40)

Most-billed visit code 99214

Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

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.

ERNESTO P GIDAYA MD

Anesthesiology

1111 W LA PALMA AVE
ANAHEIM, CA 92801

Orange County (714) 774-1450

MR. JORGE ROMERO JR.

Social Worker (Clinical)

1111 W LA PALMA AVE
ANAHEIM, CA 92801

Orange County (714) 774-1450

ANAHIEM MEMORIAL MEDICAL CENTER

General Acute Care Hospital

1111 W LA PALMA AVE, 1111 W LA PALMA AVENUE
ANAHEIM, CA 92801

Orange County (714) 999-3800

DR. JAKLYN RAE MCCLENDON M.D.

Pathology (Anatomic Pathology & Clinical Pathology)

1111 W LA PALMA AVE, AMMC - DEPT. OF PATHOLOGY
ANAHEIM, CA 92801

Orange County (714) 999-6075

ANAHEIM EMERGENCY MEDICAL GROUP

Emergency Medicine

1111 W LA PALMA AVE
ANAHEIM, CA 92801

Orange County (714) 774-1450

D LALANI PERERA-THANGARATNAM MD

Anesthesiology

1111 W LA PALMA AVE
ANAHEIM, CA 92801

Orange County (714) 774-1450

D LALANI PERERA-THANGARATNAM MD INC

Anesthesiology (Pain Medicine)

1111 W LA PALMA AVE
ANAHEIM, CA 92801

Orange County (714) 774-1450

LEI ZHANG M.D.

Pathology (Anatomic Pathology & Clinical Pathology)

1111 W LA PALMA AVE
ANAHEIM, CA 92801

Orange County (714) 774-1450

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 Mitchell Siy's NPI number?

The NPI number for Mitchell Siy is 1437829058. It was assigned to this individual provider in the NPPES registry on September 15, 2021.

Where is Mitchell Siy located?

Mitchell Siy practices at 1111 W La Palma Ave, Anaheim, CA 92801. The listed phone number is (714) 774-1450.

What is Mitchell Siy's specialty?

The primary specialty registered for this NPI is Nurse Practitioner with taxonomy code 363L00000X.

Is Mitchell Siy enrolled in Medicare?

Yes. Mitchell Siy is registered in the Medicare PECOS enrollment system.

Which organizations bill Medicare for Mitchell Siy's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Mitchell Siy reassigns Medicare benefits to 3 organizations: Cep America - California (Anaheim, CA), Gem Medical Group Corporation (Whittier, CA) and Can Emergency Physicians Medical Group Inc (Tustin, 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 Mitchell Siy'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 Mitchell Siy was last updated on November 3, 2021. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 4 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.