Nephrology Associates of Central Maine

Nephrology Associates has been providing high-quality medical care in Central Maine since 1977. We are committed to offering state-of-the-art, compassionate and comprehensive care for patients with all types of kidney disease or high blood pressure. Our physicians are board-certified in Internal Medicine and Nephrology.

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Chronic Kidney Disease also known as CKD or renal failure is characterized as the gradual loss of kidney function over time. Over 37 million Americans suffer from kidney disease, and 90% of these patients are unaware they have kidney disease. It is important to consult with your primary care physician and get screened for kidney disease.

The physicians and highly trained staff of Nephrology Associates are experienced with the latest technology and procedures available. We are committed to applying this knowledge and understanding to fully support and respond to the needs of our patients. We constantly work to create an environment that is mutually respectful to a person’s needs while striving to reach a positive outcome. Below you will find a list of disease states and procedures we address every day.

Our Services

The physicians and staff at Nephrology Associates are experienced with the latest technology and procedures to support our patients with compassionate and personalized care. Below is a list of services we offer.

Chronic Kidney Disease
We offer state-of-the-art, comprehensive care for the early detection, treatment, and long-term management of chronic kidney disease. Our approach combines advanced diagnostic tools with individualized treatment plans designed to slow disease progression, protect kidney function, and improve overall quality of life.

We deliver personalized, compassionate care based on each patient’s stage of kidney disease, medical history, and lifestyle. Our team works closely with patients to manage kidney-related complications from hypertension, diabetes, congestive heart failure and other chronic illnesses. We also provide coordinated care for patients with rheumatologic and oncologic conditions.

Our team is committed to early intervention, close monitoring, and proactive treatment strategies to help patients maintain kidney health and avoid complications whenever possible.

Acute Kidney Failure
We treat acute kidney failure both in our office and at local hospitals.

Dialysis
If dialysis is needed, we offer several options. Our team will help determine the best treatment for you and your family:

  • Hemodialysis: Uses an artificial kidney to filter waste from your blood through a permanent access in your arm. Typically done three times weekly, either at home with a helper or in a center.

  • Home Dialysis Training Facilities and Transitional Care Units: prioritizing in home dialysis training for peritoneal and hemodialysis through Fresenius Medical Care

    • Gardiner Dialyisis Center(Gardiner, ME)

    • Greater Lewiston Dialysis Center(Lewiston, ME)

  • Outpatient Dialysis Facilities: We provide care through several outpatient dialysis clinics owned and operated by Fresenius Medical Care

    • Lewiston-Auburn Kidney Center (710 Main Street, Lewiston, ME)

    • Androscoggin Kidney Center (Minot Avenue, Auburn, ME)

    • Kennebec Kidney Center (Augusta, ME)

    • Coastal Dialysis Center(Bath, ME)

    • Greater Lewiston Kidney Center (Lisbon St, Lewiston, ME)

    • Gardiner Dialyisis Center(Gardiner, ME)

    • Umbagog Kidney Center(Wilton, ME)

Electrolyte Abnormalities
We evaluate and treat metabolic, hormonal, and electrolyte issues affecting kidney health.

Hypertension
We provide specialized care for managing high blood pressure, resistant hypertension and secondary forms of Hypertension.

Kidney Biopsy
Biopsies are performed through expert Interventional Radiology Care at Central Maine Medical Center using CAT scan or ultrasound guidance to diagnose kidney conditions.

Kidney Stone Prevention
We investigate causes and design personalized prevention plans.

Kidney Transplant Care
We provide comprehensive care before and after kidney transplant, with access to fellowship-trained nephrologists.

Inpatient Dialysis
Both hemodialysis and peritoneal dialysis are offered at Central Maine Medical Center

Patient Information FAQ

Find answers to the most common questions about your visit to Nephrology Associates of Central Maine.

  • To make your first visit smooth and successful:

    • Confirm your appointment time and location.

    • Get directions ahead of time.

    • Arrive 15 minutes early.

    • Bring all of your medication bottles.

    • Bring your insurance cards.

    • Be prepared to provide a urine sample.

    • Your current medications in their original containers.

    • All insurance cards (especially if anything has changed).

    • If labs were ordered, please get them drawn at least 3–5 days before your appointment so your provider can review them in advance.

  • Yes! We have pdf forms available for you to download.

    • Bring your insurance card to every appointment.

    • We participate in most insurance plans.

    • Co-pays are expected at the time of your visit.

    • If we do not participate in your plan, or you are uninsured, full payment is expected at the time of service.

    • Questions? Our billing staff is happy to assist with payment options or insurance concerns.

    • AARP

    • Aetna

    • Anthem Blue Cross Blue Shield

    • Bankers Life

    • Champus

    • Cigna HealthCare

    • Federal Blue Cross

    • Harvard Pilgrim Health Care

    • Health Plans (Community Health Options)

    • Mailhandlers

    • MaineCare (Medicaid)

    • Maine Municipal Employees Health Trust

    • Martin’s Point

    • Railroad Medicare

    • Tricare

    • VA

    • AARP Medicare

    • Aetna Medicare

    • Anthem Medicare

    • Generations Advantage

    • Humana

    • Martin’s Point

    • Today’s Options

    • United Healthcare

    • Wellcare

    If your plan isn’t listed, please call us. We may still be able to accept your insurance or help you understand out-of-network options.

About Our Team

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    Andrew J. Thornton MD

    Dr. Thornton has been practicing nephrology in Maine for the past twenty years. He completed medical school at Boston University. He trained in an Internal Medicine Residency and a Nephrology fellowship at Boston Medical Center in Boston, Massachusetts. Dr. Thornton is board certified by the American Board of Internal Medicine in Internal Medicine and Nephrology. Dr. Thornton is a clinical instructor of medical students from The University of New England School of Medicine. Dr. Thornton is active in treating all forms of kidney disease with special interests in hypertension, chronic kidney disease, and critical care nephrology.

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    Matthew Pyenta, DO

    Dr. Pyenta is a native of Michigan. He earned his medical degree at the Des Moines University College of Osteopathic Medicine. He completed his Internal Medicine residency and General Nephrology Fellowship training at St. John Detroit Riverview Hospital in Detroit, MI. He has special interest in renal transplantation patients and he has completed a Transplant Nephrology Fellowship at St. John Hospital and Medical Center in Detroit. He is board certified in Internal Medicine and Nephrology.

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    Jeremy Wright DO

    Dr. Wright joined Nephrology Associates in 2018. He completed medical school at the University Of New England, internal medicine residency at the University of Massachusetts in Worcester, and nephrology fellowship at Maine Medical Center in Portland, Maine. He is board certified in internal medicine and nephrology. In addition to general care for patients with kidney disease, special interests include polycystic kidney disease and hypertension.

  • Kim Kosiavelon NP

    Kim joined Nephrology Associates in 2020. She earned her BSN from the University of Southern Maine and her MSN from Saint Joseph's College of Maine. She is board certified in Family Practice by the American Academy of Nurse Practitioners.

    Before becoming a nurse practitioner, Kim worked as a registered nurse in the Intensive Care Unit at Central Maine Medical Center. She also spent several years teaching in clinical settings as part of the undergraduate nursing programs at both the University of Southern Maine and Saint Joseph's College.

  • Dimitri Opolinsky, DO

    Dr. Opolinsky received his baccalaureate degree from Queens College and his medical degree from the New York Institute of Technology College of Osteopathic Medicine. He completed his Internal Medicine residency, including a year as Chief Resident, and then his Nephrology fellowship at Maine Medical Center in Portland, Maine. Since then, Dr. Opolinsky has practiced in central Maine, serving as both a Nephrologist and a Hospital Medicine physician. He has worked with Nephrology Associates of Central Maine since 2024.

Educational Resources

Where to learn more about kidney disease

Your healthcare provider is always the best source of information about your health. Because no two patients are alike, personalized advice is essential. However, the following trusted websites offer helpful and reliable information on kidney disease:

Our Office Locations

Dialysis Units.

Fresenius Kidney Care Androscoggin
110 Minot Ave, Auburn, ME 04210

Fresenius Kidney Care Lewiston
47 Mollison Way, Lewiston, ME 04240

Fresenius Kidney Care Bath
55 Congress Ave, Bath, ME 04530

Fresenius Kidney Care Kennebec
104 Civic Center Dr, Augusta, ME 04330

Fresenius Kidney Care Gardiner
46 Summer St, Gardiner, ME 04345

Fresenius Kidney Care Umbagog
73 Allen St, Wilton, ME 04294

Fresenius Kidney Care Greater Lewiston
987 Main St, Lewiston, ME 04240

Fresenius Kidney Care Gardiner
46 Summer St, Gardiner, ME 04345

Book an Appointment

Patients are seen at our headquarters in Lewiston and all of our branch offices located throughout Central and Western Maine. To schedule an appointment for all locations, please call our receptionist at 207-783-1449.

Book an Appointment Using our Online Portal

After hours, our answering service will take your phone number and direct it to the doctor on call. Please keep the line clear and your call will be returned as soon as possible. Have the number of your pharmacy handy in case you need a prescription.