Doctor profile · Federal record

Dr. William Duff, MD

Nephrology Physician (CMS: Nephrology) · Louisville, KY

  • NPI 1366446213
  • Accepts Medicare
  • 36 yrs in practice
  • Male
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
6400 Dutchmans Pkwy, Ste 250
Louisville, KY 402053340
(502) 587-9660
fax (502) 540-5615

Credentials & registration

NPPES · NUCC
NPI registered
June 2005 — 21 yrs on file
Profile last updated
August 29, 2007
Year of graduation
1990 — 36 yrs since
Specialty taxonomy
207RN0300X — NUCC code
State license (1)
Kentucky #29503
Medicaid
KY #64295033

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1366446213. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
2,227
Distinct HCPCS
10
Medicare allowed
$213,970
HCPCS Description Services Patients Avg allowed
99232 Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes 816 215 $75
99213 Established patient office or other outpatient visit, 20-29 minutes 454 301 $67
81003 Automated urinalysis test 219 175 $2
90960 Dialysis services, 4 or more physician visits per month (20 years or older) 216 25 $343
99490 Chronic care management services, first 20 minutes of clinical staff time directed by health care professional, per calendar month 96 43 $55
99222 Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes 88 82 $123
99214 Established patient office or other outpatient visit, 30-39 minutes 85 75 $91
99231 Subsequent hospital care with straightforward or low level of medical decision making, per day, if using time, at least 25 minutes 77 29 $47
99204 New patient office or other outpatient visit, 45-59 minutes 52 52 $152
99221 Initial hospital care with straightforward or low level of medical decision making, per day, if using time, at least 40 minutes 40 38 $79

In context: peer comparison

Among 25 peers in Louisville Nephrology Physician, average services per provider: 172. This provider delivers 13× the peer median.

Open Payments

Industry payments received

CMS Open Payments
All-time total
$1,586
Transactions
73
Manufacturers
15
Payer (manufacturer) Industry Txns Amount
Boehringer Ingelheim Pharmaceuticals, INC. 6 $306.41
Amgen INC. 12 $243.58
Bayer Healthcare Pharmaceuticals INC. 14 $165.03
Travere Therapeutics, INC. 6 $158.06
Alexion Pharmaceuticals, INC. 5 $116.95
Mallinckrodt Hospital Products INC. 4 $98.56
Fresenius USA Marketing, INC. 5 $84.11
Vifor Pharma, INC. 4 $79.54
Novartis Pharmaceuticals Corporation 4 $78.23
Otsuka America Pharmaceutical, INC. 4 $64.55
AstraZeneca Pharmaceuticals Lp 3 $45.52
Ardelyx, INC. 2 $33.00
Opko Pharmaceuticals, LLC 2 $30.49
Genzyme Corporation 1 $29.26
Aurinia Pharma U.S., INC. 1 $19.38

By nature of payment

Food and Beverage
$1,555
Education
$30

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
1,407
Patients
544
Total drug cost
$54,327
Drug Type Claims Patients Total cost
Amlodipine Besylate Generic 203 77 $1,784
Allopurinol Generic 160 63 $2,986
Calcitriol Generic 148 48 $2,864
Losartan Potassium Generic 140 58 $1,709
Furosemide Generic 130 54 $1,009
Torsemide Generic 125 52 $3,959
Hydralazine Hcl Generic 116 48 $2,448
Lisinopril Generic 101 38 $758
Spironolactone Generic 71 28 $848
Hydrochlorothiazide Generic 42 14 $158

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. William Duff's medical specialty?
Dr. William Duff practices Nephrology Physician in Louisville, KY.
Where does Dr. William Duff practice?
Dr. William Duff practices at 6400 Dutchmans Pkwy, Louisville, KY 402053340. Office phone: 5025879660.
What is Dr. William Duff's NPI?
Dr. William Duff's National Provider Identifier (NPI) is 1366446213, issued by NPPES.
Does Dr. William Duff accept Medicare assignment?
Yes. Dr. William Duff accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. William Duff commonly perform?
Top Medicare-reported procedures in 2023: Subsequent hospital care with moderate levelof medical decision making (HCPCS 99232); Established patient office or other outpatient visit (HCPCS 99213); Automated urinalysis test (HCPCS 81003). Source: CMS Medicare Physician & Other Practitioners file.