Dr Mary Chen, MD - Medicare Internal Medicine in Walnut, CA

  1. Home
  2. Internal Medicine
  3. CA
  4. Walnut
Dr Mary Chen, MD is a medicare enrolled "Internal Medicine" physician in Walnut, California. She graduated from medical school in 1985 and has 39 years of diverse experience with area of expertise as Internal Medicine. Her current practice location is 18780 Amar Rd, Suite 107, Walnut, California. You can reach out to her office (for appointments etc.) via phone at (626) 810-6777.

Dr Mary Chen is licensed to practice in California (license number A78207) and she also participates in the medicare program. She accepts medicare assignments (which means she accepts the Medicare-approved amount; you will not be billed for any more than the Medicare deductible and coinsurance) and her NPI Number is 1568445229.

Contact Information

Dr Mary Chen, MD
18780 Amar Rd, Suite 107,
Walnut, CA 91789-4560
(626) 810-6777
(626) 810-6687

Map and Direction




Physician's Profile

Full NameDr Mary Chen
GenderFemale
SpecialityInternal Medicine
Experience39 Years
Location18780 Amar Rd, Walnut, California
Accepts Medicare AssignmentsYes. She accepts the Medicare-approved amount; you will not be billed for any more than the Medicare deductible and coinsurance.
  Medical Education and Training:
  • Dr Mary Chen graduated from medical school in 1985
  NPI Data:
  • NPI Number: 1568445229
  • Provider Enumeration Date: 11/26/2005
  • Last Update Date: 04/23/2020
  Medicare PECOS Information:
  • PECOS PAC ID: 7416929898
  • Enrollment ID: I20040806000679

Medical Identifiers

Medical identifiers for Dr Mary Chen such as npi, medicare ID, medicare PIN, medicaid, etc.
IdentifierTypeStateIssuer
1568445229NPI-NPPES

Medical Taxonomies and Licenses

TaxonomyTypeLicense (State)Status
207Q00000XFamily Medicine A78207 (California)Secondary
207R00000XInternal Medicine A78207 (California)Primary

Medicare Reassignments

Some practitioners may not bill the customers directly but medicare billing happens through clinics / group practice / hospitals where the provider works. Medicare reassignment of benefits is a mechanism by which practitioners allow third parties to bill and receive payment for medicare services performed by them. Dr Mary Chen allows following entities to bill medicare on her behalf.
Entity NameMary Chen Md Inc
Entity TypePart B Supplier - Clinic/group Practice
Entity IdentifiersNPI Number: 1366591174
PECOS PAC ID: 0749222636
Enrollment ID: O20050601001025
Entity NameWestern Sierra Emergency Physicians Medical Group Inc
Entity TypePart B Supplier - Clinic/group Practice
Entity IdentifiersNPI Number: 1881995272
PECOS PAC ID: 6709069396
Enrollment ID: O20110318000559

Medicare Part D Prescriber Enrollment

Any physician or other eligible professional who prescribes Part D drugs must either enroll in the Medicare program or opt out in order to prescribe drugs to their patients with Part D prescription drug benefit plans. Dr Mary Chen is enrolled with medicare and thus, if eligible, can prescribe medicare part D drugs to patients with medicare part D benefits.

Mailing Address and Practice Location

Mailing AddressPractice Location Address
Dr Mary Chen, MD
18780 Amar Rd, Suite 107,
Walnut, CA 91789-4560

Ph: (626) 810-6777		Dr Mary Chen, MD
18780 Amar Rd, Suite 107,
Walnut, CA 91789-4560

Ph: (626) 810-6777

Reviews and Comments


Internal Medicine Doctors in Walnut, CA

Dr. Ankush Sharma, MD
Internal Medicine
Medicare: Accepting Medicare Assignments
Practice Location: 20927 Gartel Dr, Walnut, CA 91789
Phone: 213-709-3930    
Ann Graves Walker, MD
Internal Medicine
Medicare: Not Enrolled in Medicare
Practice Location: 1100 N Grand Ave, Bldg. 67b, Walnut, CA 91789
Phone: 909-594-5611    Fax: 909-468-3997

Medicare Program: Medicare is a federal government program which provides health insurance to people who are 65 or older. This program also covers certain younger people with disabilities (who receive Social Security Disability Insurance - SSDI), and people with End-Stage Renal Disease (permanent kidney failure requiring dialysis or a transplant, sometimes called ESRD.

Medicare Assignment: Assignment means that your doctor, provider, or supplier agrees (or is required by law) to accept the Medicare-approved amount as full payment for covered services. Most doctors, providers, and suppliers accept assignment, but you should always check to make sure. Participating providers have signed an agreement to accept assignment for all Medicare-covered services.

NPI Number: The National Provider Identifier (NPI) is a unique identification number for covered health care providers. The NPI must be used in lieu of legacy provider identifiers in the HIPAA standards transactions. Covered health care providers and all health plans and health care clearinghouses must use the NPIs in the administrative and financial transactions adopted under HIPAA (Health Insurance Portability and Accountability Act).

Our Data: Information on www.medicarelist.com is built using data sources published by Centers for Medicare & Medicaid Services (CMS) under Freedom of Information Act (FOIA). The information disclosed on the NPI Registry are FOIA-disclosable and are required to be disclosed under the FOIA and the eFOIA amendments to the FOIA. There is no way to 'opt out' or 'suppress' the NPPES record data for health care providers with active NPIs.