Doctor profile · Federal record

Dr. Koen Nieman, MD

Cardiovascular Disease Physician (CMS: Cardiovascular Disease (Cardiology)) · Specialist · Stanford, CA

  • NPI 1144778143
  • Accepts Medicare
  • MIPS 75.5 / 100 · 2023
  • 28 yrs in practice
  • Licensed in 2 states
  • Male
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
300 Pasteur Dr
Stanford, CA 943052200
(650) 723-4000

Credentials & registration

NPPES · NUCC
NPI registered
September 2016 — 10 yrs on file
Profile last updated
April 24, 2024
Year of graduation
1998 — 28 yrs since
Specialty taxonomy
207RC0000X — NUCC code
State licenses (2)
California #A174597 · ZZ #29048831401

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1144778143. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
3,680
Distinct HCPCS
10
Medicare allowed
$189,268
HCPCS Description Services Patients Avg allowed
93306 Ultrasound of heart with color-depicted blood flow, rate, direction and valve function 956 931 $79
93010 Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only 786 637 $9
93321 Ultrasound of heart blood flow, valves and chambers, follow-up 305 292 $8
93308 Ultrasound of heart, follow-up 269 257 $29
93306 Ultrasound of heart with color-depicted blood flow, rate, direction and valve function 185 185 $203
93325 Ultrasound of heart with color-depicted blood flow, rate and valve function 177 174 $4
93350 Ultrasound of heart during rest, exercise and/or drug-induced stress with report 166 166 $79
93016 Exercise or drug-induced heart stress test with electrocardiogram (ecg) with supervision by physician 158 157 $25
93018 Exercise or drug-induced heart stress test with electrocardiogram (ecg) with review by physician 140 140 $16
93320 Ultrasound of heart blood flow, valves and chambers 129 128 $21

In context: peer comparison

Among 33 peers in Stanford Cardiovascular Disease Physician, average services per provider: 162. This provider delivers 23× the peer median.

Open Payments

Industry payments received

CMS Open Payments
All-time total
$5,011
Transactions
7
Manufacturers
4
Payer (manufacturer) Industry Txns Amount
Novartis Pharmaceuticals Corporation 2 $4,640.05
Cleerly, INC. 2 $195.72
Siemens Medical Solutions USA, INC. 2 $150.49
Heartflow, INC. 1 $24.43

By nature of payment

Compensation for Services Other Than Consulting, Including Serving As Faculty or As A Speaker at A Venue Other Than A Continuing Education Program
$4,550
Food and Beverage
$461

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
129
Patients
11
Total drug cost
$17,875
Drug Type Claims Patients Total cost
Atorvastatin Calcium Generic 31 11 $625
Lisinopril Generic 20 0 $167
Metoprolol Succinate Generic 18 0 $198
Carvedilol Generic 17 0 $383
Amlodipine Besylate Generic 16 0 $125
Losartan Potassium Generic 14 0 $139
Eliquis (Apixaban) Brand 13 0 $16,237

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. Koen Nieman's medical specialty?
Dr. Koen Nieman practices Cardiovascular Disease Physician in Stanford, CA.
Where does Dr. Koen Nieman practice?
Dr. Koen Nieman practices at 300 Pasteur Dr, Stanford, CA 943052200. Office phone: 6507234000.
What is Dr. Koen Nieman's NPI?
Dr. Koen Nieman's National Provider Identifier (NPI) is 1144778143, issued by NPPES.
Does Dr. Koen Nieman accept Medicare assignment?
Yes. Dr. Koen Nieman accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Koen Nieman commonly perform?
Top Medicare-reported procedures in 2023: Ultrasound of heart with color-depicted blood flow, rate, direction and valve function (HCPCS 93306); Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only (HCPCS 93010); Ultrasound of heart blood flow, valves and chambers, follow-up (HCPCS 93321). Source: CMS Medicare Physician & Other Practitioners file.