What is William Riesen's specialty?

William Riesen (NPI 1548377997) is a Medicare-billing provider whose primary specialty is Internal Medicine in Mason City, IA.

Where does William Riesen practice?

William Riesen practices in Mason City, IA, based on the location reported in the CMS Medicare provider datasets for NPI 1548377997.

How much does Medicare pay William Riesen?

William Riesen (NPI 1548377997) received approximately $116K in total Medicare Part B payments, serving 1,815 beneficiaries, per the CMS Medicare Physician & Other Practitioners dataset.

PROVIDER PROFILE · NPI 1548377997

William RiesenMD

Internal MedicineMason City, IAI

MEDICARE UTILIZATION · PART B · 2024

Total beneficiaries

2,570

Unique beneficiaries

—

Total services

3,848

Distinct HCPCS

Medicare payment

$113K

Peer benchmark

Total Medicare services vs. 418 Internal Medicine providers in IA — top quintile (cohort median 722).

PRESCRIBING · PART D · 2024

Total Rx claims

6,584

Beneficiaries

—

Total drug cost

$399K

Distinct drugs

102

Brand share

19.2%

Top prescribed drugs

Atorvastatin Calcium435 claims

Levothyroxine Sodium283 claims

Lisinopril270 claims

Losartan Potassium266 claims

Omeprazole233 claims

QUALITY · MIPS · 2024

Final MIPS score

0.0

Quality

0.0

Cost

0.0

Improvement activities

0.0

Promoting interop.

0.0

Payment adjustment

-9.00%

Group

INDUSTRY PAYMENTS · OPEN PAYMENTS · 2025

No data available for this provider in 2025.

REFERRAL NETWORK

Where William Riesen's patients come from & go

Directional shared-patient flow from Medicare claims — who sends patients to this provider (inbound) and where this provider's patients go next (outbound). 79 inbound referrers · 0 outbound destinations.

Receives referrals from

Inbound — who sends patients here

Physician	Patients	Visits
MERCY HEALTH SERVICES-IOWA CORP	958	12,095
Gary Swenson Diagnostic Radiology · Mason City, IA	210	548
Travis Petree Internal Medicine · Minot, ND	179	611
William Matthews Diagnostic Radiology · Mason City, IA	166	562
JANSON, BRAD	149	391
Robert Berg Interventional Radiology · Mason City, IA	148	419
Byron Beasley Cardiology · Mason City, IA	128	653
NPI 1104933142	120	874
HARLAN, BRUCE	120	893
Ryan Smith Diagnostic Radiology · Mason City, IA	112	423
Satinderjit Singh Emergency Medicine · Mason City, IA	108	364
Gholam Zadeii Internal Medicine · Rancho Mirage, CA	100	428

Refers patients to

Outbound — where patients go next

No outbound pairs above the suppression threshold.

Source: CMS Physician Shared Patient Patterns (30-day window, Medicare FFS). Direction = a beneficiary seen by the first provider, then the second, within 30 days; a proxy for referral, not a documented referral. Pairs with fewer than 11 shared beneficiaries are suppressed.

CROSS-REFERENCE

Related data on other Healthparse brands

ProviderScore

OIG/SAM exclusion screening, sanctions history

Healthparse Signals

Monitor this provider for changes — dated NPI change events