Doctor profile · Federal record

Dr. Cassandra Williams, MD

Internal Medicine Physician (CMS: Internal Medicine) · Internal Medicine Physician · Amherst, NY

  • NPI 1558546820
  • Accepts Medicare
  • 21 yrs in practice
  • Licensed in 2 states
  • Female
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
3980A Sheridan Dr Ste 200
Amherst, NY 142261741
(716) 309-4772
Mailing address
Po Box 488
Buffalo, NY 142400488

Credentials & registration

NPPES · NUCC
NPI registered
January 2008 — 18 yrs on file
Profile last updated
October 30, 2020
Year of graduation
2005 — 21 yrs since
Specialty taxonomy
207R00000X — NUCC code
State licenses (2)
New York #302772 · North Carolina #200800022
Medicaid (3)
NY #06012940 · SC #N0002C · NC #5909659

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1558546820. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
811
Distinct HCPCS
5
Medicare allowed
$90,788
HCPCS Description Services Patients Avg allowed
99309 Subsequent nursing facility care with moderate level of medical decision making, per day, if using time, at least 30 minutes 625 180 $102
99306 Initial nursing facility care with high level of medical decision making, per day, if using time, at least 45 minutes 129 106 $172
99308 Subsequent nursing facility care with straightforward level of medical decision making, per day, if using time, at least 15 minutes 24 22 $71
99316 Nursing facility discharge management, more than 30 minutes 18 18 $123
99497 Advance care planning, first 30 minutes 15 15 $73

In context: peer comparison

Among 9 peers in this city , average services per provider: 89. This provider delivers 9.1× the peer median.

Open Payments

Industry payments received

CMS Open Payments
All-time total
$232
Transactions
2
Manufacturers
2
Payer (manufacturer) Industry Txns Amount
AstraZeneca Pharmaceuticals LP 1 $116.50
ACADIA Pharmaceuticals Inc 1 $115.38

By nature of payment

Food and Beverage
$232

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
8,537
Patients
938
Total drug cost
$431,405
Drug Type Claims Patients Total cost
Levothyroxine Sodium Generic 1,156 70 $11,096
Atorvastatin Calcium Generic 752 96 $19,964
Furosemide Generic 725 69 $4,959
Eliquis (Apixaban) Brand 714 58 $203,878
Amlodipine Besylate Generic 615 82 $7,481
Sertraline Hcl Generic 565 57 $11,741
Levetiracetam Generic 532 56 $33,750
Metoprolol Succinate Generic 473 55 $11,914
Duloxetine Hcl Generic 466 54 $40,303
Divalproex Sodium Generic 457 57 $35,902

Frequently asked questions

Auto-generated from federal data
What is Dr. Cassandra Williams's medical specialty?
Dr. Cassandra Williams practices Internal Medicine Physician in Amherst, NY.
Where does Dr. Cassandra Williams practice?
Dr. Cassandra Williams practices at 3980A Sheridan Dr Ste 200, Amherst, NY 142261741. Office phone: 7163094772.
What is Dr. Cassandra Williams's NPI?
Dr. Cassandra Williams's National Provider Identifier (NPI) is 1558546820, issued by NPPES.
Does Dr. Cassandra Williams accept Medicare assignment?
Yes. Dr. Cassandra Williams accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Cassandra Williams commonly perform?
Top Medicare-reported procedures in 2023: Subsequent nursing facility care with moderate level of medical decision making (HCPCS 99309); Initial nursing facility care with high level of medical decision making (HCPCS 99306); Subsequent nursing facility care with straightforward level of medical decision making (HCPCS 99308). Source: CMS Medicare Physician & Other Practitioners file.