Cassandra Williams, MD - Medicare Internal Medicine in Amherst, NY

Cassandra Williams, MD is a medicare enrolled "Internal Medicine" physician in Amherst, New York. Her current practice location is 3980a Sheridan Dr Ste 200, Amherst, New York. You can reach out to her office (for appointments etc.) via phone at (716) 309-4772.

Cassandra Williams is licensed to practice in New York (license number 302772) and she also participates in the medicare program. She does not accept medicare assignments directly but she may accept medicare through third-party (refer to Reassignment section below) and may also prescribe medicare part D drugs. Her NPI Number is 1558546820.

Contact Information

Cassandra Williams, MD
3980a Sheridan Dr Ste 200,
Amherst, NY 14226-1741
(716) 309-4772
Not Available

Map and Direction




Physician's Profile

Full NameCassandra Williams
GenderFemale
SpecialityInternal Medicine
Location3980a Sheridan Dr Ste 200, Amherst, New York
Accepts Medicare AssignmentsMedicare enrolled and may accept medicare through third-party reassignment. May prescribe medicare part D drugs.
  NPI Data:
  • NPI Number: 1558546820
  • Provider Enumeration Date: 01/07/2008
  • Last Update Date: 10/30/2020
  Medicare PECOS Information:
  • PECOS PAC ID: 0345313532
  • Enrollment ID: I20080722000113

Medical Identifiers

Medical identifiers for Cassandra Williams such as npi, medicare ID, medicare PIN, medicaid, etc.
IdentifierTypeStateIssuer
1558546820NPI-NPPES
06012940MedicaidNY
N0002CMedicaidSC
5909659MedicaidNC

Medical Taxonomies and Licenses

TaxonomyTypeLicense (State)Status
207R00000XInternal Medicine 200800022 (North Carolina)Secondary
207R00000XInternal Medicine 302772 (New York)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. Cassandra Williams allows following entities to bill medicare on her behalf.
Entity NameCaromont Medical Group Inc
Entity TypePart B Supplier - Clinic/group Practice
Entity IdentifiersNPI Number: 1356314272
PECOS PAC ID: 3577476258
Enrollment ID: O20031201000070

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. Cassandra Williams 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
Cassandra Williams, MD
Po Box 488,
Buffalo, NY 14240-0488

Ph: (866) 853-9551
Cassandra Williams, MD
3980a Sheridan Dr Ste 200,
Amherst, NY 14226-1741

Ph: (716) 309-4772

Reviews and Comments


Internal Medicine Doctors in Amherst, NY

Ahmad Mafi, DO
Internal Medicine
Medicare: Accepting Medicare Assignments
Practice Location: 3980a Sheridan Dr Ste 200, Amherst, NY 14226
Phone: 716-833-2200    
Dawn S Harbatkin, MD
Internal Medicine
Medicare: Accepting Medicare Assignments
Practice Location: 3980 Sheridan Dr, Amherst, NY 14226
Phone: 716-250-2000    Fax: 716-819-3821
Richard Vienne, MD
Internal Medicine
Medicare: Not Enrolled in Medicare
Practice Location: 1185 Sweet Home Rd, Amherst, NY 14226
Phone: 716-689-0040    Fax: 716-568-2334
Bradley Carrier, MD, MS
Internal Medicine
Medicare: Accepting Medicare Assignments
Practice Location: 2350 Maple Rd, Amherst, NY 14221
Phone: 716-688-6500    
Dr. Rakhi Shah Barkowski, M.D.
Internal Medicine
Medicare: Accepting Medicare Assignments
Practice Location: 3980a Sheridan Dr Ste 200, Amherst, NY 14226
Phone: 716-852-4772    
Riffat Sadiq, M.D.
Internal Medicine
Medicare: Accepting Medicare Assignments
Practice Location: 4979 Harlem Rd, Suite 1, Amherst, NY 14226
Phone: 716-923-4380    Fax: 716-923-4384
Kristin Ann Matteson, D.O.
Internal Medicine
Medicare: Accepting Medicare Assignments
Practice Location: 1306 Sweet Home Rd, Amherst, NY 14228
Phone: 716-838-3188    Fax: 716-838-1297

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.