WILLIAM CHUNGHUN SIM MD
NPI 1437256906
Internal Medicine in Downey, CA

Q: What is William Sim's NPI number?

The NPI number for William Sim is 1437256906. It was assigned to this individual provider in the NPPES registry on September 19, 2006.

Q: What is William Sim's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Q: When was this NPI record last updated?

The NPPES record for William Sim was last updated on December 20, 2011. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 14 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 19, 2006PECOS EnrolledAccepts Medicare Assignment

75/100

CMS Quality Rating

11480 BROOKSHIRE AVE, 200, DOWNEY, CA 90241(562) 806-0874(562) 927-4801 Get Directions Write a Review

NPPES record last updated: December 20, 2011. Verified against the NPPES registry weekly; last sync: October 18, 2026.

On this page

About William Chunghun Sim Md NPPES

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

WILLIAM CHUNGHUN SIM MD (NPI 1437256906) is an individual internal medicine provider in Downey, California, licensed in California (G72353) and active in the NPI registry since September 2006. He is enrolled in Medicare PECOS and is a graduate of Stanford University School Of Medicine (1990).

NPPES Registry Identity

NPI1437256906

Entity TypeIndividualMale

Primary Taxonomy207R00000X

Provider Legal NameWILLIAM CHUNGHUN SIMCredential: MD

Location Address11480 BROOKSHIRE AVE, 200Downey, CA 90241-9998

Mailing Address11480 Brookshire Ave, 200Downey, CA 90241-9998 · (562) 806-0874 · Fax (562) 927-4801

Phone(562) 806-0874

Fax(562) 927-4801

Sole ProprietorNo

Medical School CMSStanford University School Of MedicineGraduated 1990

Enumeration DateSeptember 19, 2006

Last NPPES UpdateDecember 20, 2011

✔ NPI 1437256906 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians

Taxonomy Code207R00000X

License✔ Licensed in CA · G72353

Definition

A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.

11480 BROOKSHIRE AVE, Downey, CA 90241

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Other Identifiers 3

Medicare PINWG72352CCA

Medicare UPINF52816CA

Medicaid00G723520CA

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

William Chunghun Sim Md 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.

PECOS PAC ID5698800910

PECOS Enrollment IDI20100311000876

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 Reassignment

Medicare enrollment records show William Sim reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Frischer Medical Group Inc

Same address

Internal Medicine

11480 BROOKSHIRE AVE, 200
Downey, CA 90241

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

NPI 1659328797 (562) 806-0874

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 16

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.

Residence visit for established patient with moderate level of medical decision making, per day, if using time, at least 40 minutes 99349

An established patient home visit is a medical appointment conducted at your home, typically lasting around 40 minutes. This service is ideal for patients who may find it difficult to travel to a healthcare facility. During this visit, a healthcare professional will evaluate your health status, manage your care, and answer any health-related questions you may have.

1,647 services315 patients

Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more 99214

This is a routine check-up for patients who have previously visited our clinic. It involves a comprehensive review of your health and any ongoing treatments. The consultation lasts between 30-39 minutes, allowing enough time to discuss any concerns.

677 services331 patients

Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more 99213

This is a routine visit for patients who have already been seen by the healthcare provider. During this approximately 20-29 minute appointment, your health status will be evaluated and any necessary treatments or tests will be discussed. It's a chance to address any health concerns you may have.

640 services238 patients

Residence visit for established patient with low level of medical decision making, per day, if using time, at least 30 minutes 99348

An established patient home visit is a 25-minute appointment where a healthcare provider visits you at your home. This service is for patients who have previously been seen by the provider. It includes a check-up and discussion about your health concerns.

564 services235 patients

Physician or allowed practitioner supervision of a patient receiving medicare-covered services provided by a participating home health agency (patient not present) requiring complex and multidisciplinary care modalities involving regular physician or allow G0181

This service involves a physician overseeing your care while you receive Medicare-covered services from a home health agency. The care you're receiving is complex and involves various disciplines. The physician isn't physically present but regularly supervises your treatment to ensure optimal health outcomes.

423 services245 patients

Injection, triamcinolone acetonide, not otherwise specified, 10 mg J3301

Triamcinolone acetonide is a medication used to reduce inflammation in the body. It's given as a 10 mg injection for conditions like allergies, arthritis, or skin problems. The injection helps to decrease swelling, redness, and itching.

379 services62 patients

Chronic care management services, first 20 minutes of clinical staff time directed by health care professional, per calendar month 99490

Chronic care management services involve a healthcare professional directing clinical staff in managing your chronic conditions. This includes the first 20 minutes per month of services like medication management, care coordination, and health monitoring to help improve your health and quality of life.

215 services30 patients

Residence visit for new patient with high level of medical decision making, per day, if using time, at least 75 minutes 99345

A new patient home visit is a comprehensive 75-minute appointment conducted at your home. The healthcare professional will assess your health, discuss any concerns, and create a personalized care plan. It's convenient, comfortable, and tailored to your specific needs.

125 services125 patients

Injection of drug or substance under skin or into muscle 96372

This procedure involves administering medication directly under the skin or into a muscle. A small needle is used to inject the drug, allowing it to be absorbed quickly into the bloodstream. It's a common method for delivering a variety of medications.

109 services58 patients

Aspiration and/or injection of fluid from large joint 20610

This procedure involves using a needle to remove (aspiration) or introduce (injection) fluid into a large joint like the knee or hip. It can help diagnose conditions, relieve discomfort, or deliver medication directly to the joint.

53 services36 patients

Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report 93000

An electrocardiogram (ECG) is a non-invasive test that records your heart's electrical activity. Using 12 leads attached to your body, it captures data to help identify heart conditions. A doctor interprets the results and provides a report.

51 services46 patients

Urinalysis, manual test 81002

A urinalysis is a simple, non-invasive test that checks the urine for various elements such as sugar, protein, and signs of infection. It can help detect many common conditions, including kidney disease and diabetes. The manual test involves a lab technician examining a urine sample.

47 services29 patients

Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more 99215

This service involves a follow-up appointment for existing patients, lasting between 40 to 54 minutes. During this time, your healthcare provider will assess your current health status, discuss any changes or concerns, review your treatment plan, and answer any questions you may have.

39 services34 patients

Established patient office or other outpatient visit with straightforward medical decision making, if using time, 10 minutes or more 99212

This is a routine check-up for patients who have previously seen the doctor. During this 10-19 minute visit, the doctor will review your health status, discuss any concerns, and manage ongoing treatments or medications. It's a chance to ensure your health is on track.

27 services23 patients

New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more 99204

This is a first-time office or outpatient visit lasting between 45-59 minutes. The healthcare provider evaluates your health, discusses your medical history, and may suggest further tests or treatments. It's an opportunity to ask questions and understand your health better.

20 services20 patients

Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit G0439

An annual wellness visit is a yearly appointment with your primary care provider to create or update a personalized prevention plan. This plan helps prevent illness based on your current health and risk factors. It's a subsequent visit, meaning it follows an initial assessment.

12 services12 patients

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 90241 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

$142.39 typical visit price

range $62.96 – $187.60

Typical copayment $35.59 (range $15.74 – $46.90)

Most-billed visit code 99204

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.

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.

75/100

MIPS Final ScoreMerit-based Incentive Payment System · CMS Quality Payment Program

Scored as part of a group practice

Reported Quality Measures

Care Plan

Percentage of patients aged 65 years and older who have an advance care plan or surrogate decision maker documented in the medical record that an advance care plan was discussed but the patient did not wish or was not able to name a surrogate decision maker…

100%259 patients5/55-star benchmark: 100%

Colorectal Cancer Screening

Percentage of adults 50-75 years of age who had appropriate screening for colorectal cancer

100%133 patients5/55-star benchmark: 100%

Preventive Care and Screening: Body Mass Index (BMI) Screening and Follow-Up Plan

Percentage of patients aged 18 years and older with a BMI documented during the current encounter or during the previous twelve months AND with a BMI outside of normal parameters, a follow-up plan is documented during the encounter or during the previous…

100%272 patients5/55-star benchmark: 100%

Providers report different measures because they deliver different services; reporting more or less information is not a reflection of quality. Star ratings appear only where CMS assigned them.

Referred Medical Equipment & Supplies CMS DME claims 24

Durable medical equipment, devices and supplies this provider ordered from DME suppliers for patients, from Medicare fee-for-service claims.

Blood glucose test or reagent strips for home blood glucose monitor, per 50 strips A4253

DME-Other DME · category DE017N

16 suppliers76 claims185 services$6.02 avg. paid by Medicare

Spring-powered device for lancet, each A4258

DME-Other DME · category DE000N

2 suppliers20 claims20 services$1.71 avg. paid by Medicare

Lancets, per box of 100 A4259

DME-Medical/Surgical Supplies · category DA000N

12 suppliers54 claims66 services$1.10 avg. paid by Medicare

Bedside drainage bag, day or night, with or without anti-reflux device, with or without tube, each A4357

DME-Orthotic Devices · category DF000N

1 supplier12 claims24 services$9.39 avg. paid by Medicare

Tubing with integrated heating element for use with positive airway pressure device A4604

DME-Other DME · category DE001N

3 suppliers12 claims12 services$35.04 avg. paid by Medicare

Tracheal suction catheter, any type other than closed system, each A4624

DME-Other DME · category DE000N

1 supplier12 claims360 services$2.55 avg. paid by Medicare

Urinary drainage bag, leg or abdomen, latex, with or without tube, with straps, each A5112

DME-Orthotic Devices · category DF000N

1 supplier12 claims12 services$33.47 avg. paid by Medicare

For diabetics only, fitting (including follow-up), custom preparation and supply of off-the-shelf depth-inlay shoe manufactured to accommodate multi-density insert(s), per shoe A5500

DME-Orthotic Devices · category DF000N

4 suppliers13 claims26 services$55.90 avg. paid by Medicare

For diabetics only, multiple density insert, direct formed, molded to foot after external heat source of 230 degrees fahrenheit or higher, total contact with patient's foot, including arch, base layer minimum of 1/4 inch material of shore a 35 durometer or 3/16 inch material of shore a 40 durometer (or higher), prefabricated, each A5512

DME-Orthotic Devices · category DF000N

4 suppliers13 claims78 services$24.83 avg. paid by Medicare

Cushion for use on nasal mask interface, replacement only, each A7032

DME-Other DME · category DE001N

4 suppliers18 claims100 services$14.75 avg. paid by Medicare

Nasal interface (mask or cannula type) used with positive airway pressure device, with or without head strap A7034

DME-Other DME · category DE001N

5 suppliers24 claims24 services$42.83 avg. paid by Medicare

Headgear used with positive airway pressure device A7035

DME-Other DME · category DE001N

7 suppliers16 claims16 services$15.56 avg. paid by Medicare

Tubing used with positive airway pressure device A7037

DME-Other DME · category DE001N

5 suppliers13 claims13 services$10.91 avg. paid by Medicare

Filter, disposable, used with positive airway pressure device A7038

DME-Other DME · category DE001N

7 suppliers26 claims151 services$1.68 avg. paid by Medicare

Tracheostomy tube collar/holder, each A7526

DME-Orthotic Devices · category DF000N

1 supplier12 claims48 services$3.28 avg. paid by Medicare

Walker, folding, wheeled, adjustable or fixed height E0143

DME-Other DME · category DE000N

6 suppliers14 claims14 services$44.08 avg. paid by Medicare

Hospital bed, semi-electric (head and foot adjustment), with any type side rails, with mattress E0260

DME-Hospital Beds · category DB000N

4 suppliers36 claims58 services$46.11 avg. paid by Medicare

Home blood glucose monitor E0607

DME-Other DME · category DE017N

2 suppliers16 claims16 services$64.12 avg. paid by Medicare

General use wheelchair seat cushion, width less than 22 inches, any depth E2601

DME-Wheelchairs · category DD021N

5 suppliers16 claims16 services$32.44 avg. paid by Medicare

General use wheelchair back cushion, width less than 22 inches, any height, including any type mounting hardware E2611

DME-Wheelchairs · category DD021N

5 suppliers17 claims17 services$145.50 avg. paid by Medicare

Albuterol, inhalation solution, fda-approved final product, non-compounded, administered through dme, unit dose, 1 mg J7613

DME-Drugs Administered Through DME · category DG006N

2 suppliers11 claims2,760 services$0.03 avg. paid by Medicare

Lightweight wheelchair K0003

DME-Wheelchairs · category DD000N

2 suppliers55 claims147 services$31.03 avg. paid by Medicare

Supply allowance for therapeutic continuous glucose monitor (cgm), includes all supplies and accessories, 1 month supply = 1 unit of service K0553

DME-Other DME · category DE017N

6 suppliers28 claims28 services$182.53 avg. paid by Medicare

Pharmacy dispensing fee for inhalation drug(s); per 30 days Q0513

DME-Other DME · category DE000N

2 suppliers11 claims11 services$26.06 avg. paid by Medicare

Dollar amounts are the average Medicare paid the supplier per service. They are not the cost to the patient.

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.

DR. VINOD D PATEL M.D.

Internal Medicine

11480 BROOKSHIRE AVE, SUITE #204
DOWNEY, CA 90241

Los Angeles County (562) 862-2775

FRISCHER MEDICAL GROUP

Internal Medicine (Gastroenterology)

11480 BROOKSHIRE AVE, 200
DOWNEY, CA 90241

Los Angeles County (562) 806-0874

THE ONCOLOGY INSTITUTE OF HOPE AND INNOVATION

Internal Medicine (Hematology & Oncology)

11480 BROOKSHIRE AVE, SUITE 309
DOWNEY, CA 90241

Los Angeles County (562) 869-1201

DR. MICHAEL SHAOYI FANG M.D.

Internal Medicine (Nephrology)

11480 BROOKSHIRE AVE, STE 302
DOWNEY, CA 90241

Los Angeles County (626) 337-2265

LAUREN RAE GILLAN PA-C

Physician Assistant

11480 BROOKSHIRE AVE, SUITE 309
DOWNEY, CA 90241

Los Angeles County (562) 869-1201

NEIL E KLEIN MD A MEDICAL CORPORATION

Surgery (Plastic and Reconstructive Surgery)

11480 BROOKSHIRE AVE, SUITE 306
DOWNEY, CA 90241

Los Angeles County (562) 861-8246

JANESSA JAMES CREADO NP

Nurse Practitioner (Family)

11480 BROOKSHIRE AVE, SUITE 308
DOWNEY, CA 90241

Los Angeles County (562) 862-3656

RITA ROY M.D.

Pediatrics

11480 BROOKSHIRE AVE, SUITE 105
DOWNEY, CA 90241

Los Angeles County (562) 622-1100

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 William Sim's NPI number?

The NPI number for William Sim is 1437256906. It was assigned to this individual provider in the NPPES registry on September 19, 2006.

Where is William Sim located?

William Sim practices at 11480 Brookshire Ave 200, Downey, CA 90241. The listed phone number is (562) 806-0874.

What is William Sim's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Is William Sim enrolled in Medicare?

Yes. William Sim 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 organization bills Medicare for William Sim's services?

According to the CMS Revalidation Reassignment List (October 2026 release), William Sim reassigns Medicare benefits to Frischer Medical Group Inc (Downey, CA). The 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 William Sim'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 William Sim was last updated on December 20, 2011. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 14 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.