Dr. William J. Riesen
- Gender: Male
- Experience: 28 years
- Graduated from: Perelman School Of Med At The University Of Pennsylvania
- Graduation year: 1993
- Sole propriator: No
- NPI: 1548377997
Dr. William J. Riesen MD
Internist
He is located at 1010 4th Street Southwest Suite 305 in Mason City, IA 50401. Can help patients with the following: Anemia, Fever, Heart Disease, Hyponatremia, Obesity, Prescription Refill. His National Provider Identifier (NPI) number is 1548377997. Appointment can be made via the phone number (641) 428-5700. He is affiliated with 2 practices and 1 hospitals.
Conditions treated
Dr. William J. Riesen, being an internist, treats the following conditions. Please be advised that this list may not be complete. For the full list of conditions treated, consult directly with Dr. William J. Riesen.
- Abdominal Pain
- Acute Pain
- Anemia
- Arthritis
- Asthma
- Atherosclerosis
- Bladder Control
- Chest Pain
- Cholecystitis
- Chronic Obstructive Pulmonary Disease (COPD)
- Common Cold
- Constipation
- Cystitis
- Diarrhea
- Edema
- Fever
- Gastroesophageal Reflux Disease (GERD)
- General Care
- Headache
- Heart Disease
- Hiatal Hernia
- High Blood Pressure
- Hot Flashes
- Hyperlipidemia
- Hyponatremia
- Influenza
- Inguinal Hernia
- Migraine
- Nausea and Vomiting
- Obesity
- Osteoporosis
- Peptic Ulcer
- Prescription Refill
- Urethritis
- Urinary Tract Infection (UTI)
Procedures Performed by Dr. William J. Riesen
ACA Marketplace (Obamacare/HealthCare.gov) plan networks
Insurers selling ACA Marketplace (HealthCare.gov) plans list Dr. William J. Riesen as in-network for the following 2026 plans.
Health plans
Ambetter Health
Network data as of Sep 15, 2026, as reported by the insurer.
Show all 16 plans from Ambetter Health
| Plan | Plan type | Network tier | New patients |
|---|---|---|---|
| Complete Gold | HMO · Gold | Preferred | Accepting new patients |
| Complete Gold + Vision + Adult Dental | HMO · Gold | Preferred | Accepting new patients |
| Elite Bronze | HMO · Expanded Bronze | Preferred | Accepting new patients |
| Elite Bronze + Vision + Adult Dental | HMO · Expanded Bronze | Preferred | Accepting new patients |
| Everyday Bronze | HMO · Expanded Bronze | Preferred | Accepting new patients |
| Everyday Bronze + Vision + Adult Dental | HMO · Expanded Bronze | Preferred | Accepting new patients |
| Everyday Gold | HMO · Gold | Preferred | Accepting new patients |
| Everyday Gold + Vision + Adult Dental | HMO · Gold | Preferred | Accepting new patients |
| Focused Silver | HMO · Silver | Preferred | Accepting new patients |
| Focused Silver + Vision + Adult Dental | HMO · Silver | Preferred | Accepting new patients |
| Standard Expanded Bronze | HMO · Expanded Bronze | Preferred | Accepting new patients |
| Standard Expanded Bronze + Vision + Adult Dental | HMO · Expanded Bronze | Preferred | Accepting new patients |
| Standard Gold | HMO · Gold | Preferred | Accepting new patients |
| Standard Gold + Vision + Adult Dental | HMO · Gold | Preferred | Accepting new patients |
| Standard Silver | HMO · Silver | Preferred | Accepting new patients |
| Standard Silver + Vision + Adult Dental | HMO · Silver | Preferred | Accepting new patients |
Medica
Network data as of Aug 5, 2024, as reported by the insurer.
Show all 9 plans from Medica
| Plan | Plan type | Network tier | New patients |
|---|---|---|---|
| Medica Insure Bronze $0 Copay PCP Visits | EPO · Expanded Bronze | Standardtier | Accepting new patients |
| Medica Insure Bronze Share | EPO · Expanded Bronze | Standardtier | Accepting new patients |
| Medica Insure Expanded Bronze Standard | EPO · Expanded Bronze | Standardtier | Accepting new patients |
| Medica Insure Gold $0 Copay PCP Visits | EPO · Gold | Standardtier | Accepting new patients |
| Medica Insure Gold Share | EPO · Gold | Standardtier | Accepting new patients |
| Medica Insure Gold Standard | EPO · Gold | Standardtier | Accepting new patients |
| Medica Insure Silver $0 Copay PCP Visits | EPO · Silver | Standardtier | Accepting new patients |
| Medica Insure Silver Share | EPO · Silver | Standardtier | Accepting new patients |
| Medica Insure Silver Standard | EPO · Silver | Standardtier | Accepting new patients |
Oscar Insurance Company
Network data as of Sep 15, 2026, as reported by the insurer.
Show all 16 plans from Oscar Insurance Company
| Plan | Plan type | Network tier | New patients |
|---|---|---|---|
| Bronze Classic 4700 | MercyOne | EPO · Expanded Bronze | Preferred | Accepting new patients |
| Bronze Classic Standard | MercyOne | EPO · Expanded Bronze | Preferred | Accepting new patients |
| Bronze Elite + PCP Saver Plus | MercyOne | EPO · Expanded Bronze | Preferred | Accepting new patients |
| Bronze Simple Breathe Easy with Enhanced COPD Benefits | MercyOne | EPO · Expanded Bronze | Preferred | Accepting new patients |
| Bronze Simple Chronic Care CKM | MercyOne | EPO · Expanded Bronze | Preferred | Accepting new patients |
| Bronze Simple Diabetes | MercyOne | EPO · Expanded Bronze | Preferred | Accepting new patients |
| Gold Classic Standard | MercyOne | EPO · Gold | Preferred | Accepting new patients |
| Gold Elite | MercyOne | EPO · Gold | Preferred | Accepting new patients |
| Secure | MercyOne | EPO · Catastrophic | Preferred | Accepting new patients |
| Silver Classic Standard | MercyOne | EPO · Silver | Preferred | Accepting new patients |
| Silver Classic | MercyOne | EPO · Silver | Preferred | Accepting new patients |
| Silver Simple Breathe Easy with Enhanced COPD Benefits | MercyOne | EPO · Silver | Preferred | Accepting new patients |
| Silver Simple Chronic Care CKM | MercyOne | EPO · Silver | Preferred | Accepting new patients |
| Silver Simple Diabetes | MercyOne | EPO · Silver | Preferred | Accepting new patients |
| Silver Simple PCP Saver | MercyOne | EPO · Silver | Preferred | Accepting new patients |
| Silver Simple Women's Health with Menopause Benefits | MercyOne | EPO · Silver | Preferred | Accepting new patients |
Wellmark Health Plan of Iowa, Inc.
Network data as of Sep 8, 2026, as reported by the insurer.
Show all 7 plans from Wellmark Health Plan of Iowa, Inc.
| Plan | Plan type | Network tier | New patients |
|---|---|---|---|
| Wellmark Bronze HDHP HMO HSA Qualified | HMO · Expanded Bronze | Wellmark Blue HMO Network | Accepting new patients at some locations |
| Wellmark Bronze Traditional HMO | HMO · Expanded Bronze | Wellmark Blue HMO Network | Accepting new patients at some locations |
| Wellmark Gold Traditional HMO | HMO · Gold | Wellmark Blue HMO Network | Accepting new patients at some locations |
| Wellmark Silver Traditional HMO | HMO · Silver | Wellmark Blue HMO Network | Accepting new patients at some locations |
| Wellmark Standard Bronze HMO | HMO · Expanded Bronze | Wellmark Blue HMO Network | Accepting new patients at some locations |
| Wellmark Standard Gold HMO | HMO · Gold | Wellmark Blue HMO Network | Accepting new patients at some locations |
| Wellmark Standard Silver HMO | HMO · Silver | Wellmark Blue HMO Network | Accepting new patients at some locations |
This covers ACA Marketplace plans only, as reported by each insurer. It does not include employer, Medicare Advantage, or state-run exchange plans, and a plan missing from this list does not mean Dr. William J. Riesen is out of network. Insurer directories can be out of date, so always confirm with the insurer and the office before your visit.
Medicare Enrollment
Dr. William J. Riesen is enrolled to bill Medicare as a Practitioner - Internal Medicine .
Bills through: North Iowa Mercy Clinics
Based on Medicare's public enrollment records as of Jul 17, 2026. This reflects Medicare fee-for-service enrollment only and says nothing about other insurance, quality, outcomes, or board certification.
Studies
PERELMAN SCHOOL OF MED AT THE UNIVERSITY OF PENNSYLVANIA
Graduated in 1993
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Questions & Answers
Where can you meet with Dr. William J. Riesen?
Dr. William J. Riesen's office is located at 1010 4th Street Southwest Suite 305 in Mason City, IA 50401.
Does Dr. William J. Riesen have affiliation with practices?
Dr. William J. Riesen is affiliated with Mercy Family Clinic-Rockwell. For the full list of practices see this list.
What conditions does Dr. William J. Riesen treat?
Dr. William J. Riesen provides treatment for Anemia, Fever, Heart Disease, Hyponatremia, Obesity, Prescription Refill. For the full list see this list.
Has Dr. William J. Riesen affiliation with hospitals?
Dr. William J. Riesen is affiliated with MERCY MEDICAL CENTER-NORTH IOWA.
Does Dr. William J. Riesen accept patients with Ambetter Health?
Yes, Dr. William J. Riesen is listed in-network for Ambetter Health through the ACA Marketplace (Obamacare/HealthCare.gov). See the Marketplace plans section for details.