Dr. Rex Mahnensmith, MD

Dr. Rex Mahnensmith, MD

Internal Medicine  |  
Male  |  
Age 66
Insurances AcceptedSave
Dr. Rex Mahnensmith, MD is an internal medicine doctor who practices in Simsbury, CT. He is 66 years old and has been practicing for 40 years. Read his story

28 Ashton Cir

Simsbury, CT 06070

Contact Information

(860) 937-7249

Insurance Accepted

  • Aetna
  • Anthem
  • Blue Cross Blue Shield
  • Blue Cross Blue Shield of Louisiana
  • Blue Cross Blue Shield of Massachusetts
  • Cigna
  • EmblemHealth
  • Harvard Pilgrim Health Care
  • Oxford Health Plans
  • UnitedHealthCare

*Please verify this information when scheduling an appointment.

Learn about Dr. Mahnensmith

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Dr. Mahnensmith's Experience

Dr. Mahnensmith's experience matches your search based on the following criteria:
  • Based on total number of patients treated over the last 12 months
  • Specializes in Internal Medicine
  • Board certified in Internal Medicine and Nephrology
  • No malpractice claims found
  • No sanctions found
  • No board actions found

Dr. Mahnensmith's bio

This content was provided by Dr. Mahnensmith "I am a God-Revering, God-Loving Servant-Physician. I grew up in rural Indiana. Worship, Basketball, Baseball and Swimming were my passions. I have loved reading. I attended College in Granville OHIO. I attended Medical School at Yale. I married in 1974, uniting in covenant relationship with my best friend and my girl friend of childhood. We have two children, now adult. We have 4 grandchildren, whom we love dearly. I love Schnauzers. I love caring for them. I have served at Duke Hospital, Medford Clinic, Rogue Valley Hospital, Miriam Hospital, Yale New Haven Hospital, Connecticut Childrens Hospital, and Stay Well Community Health Center. I have provided Geriatric Care in four Nursing Homes and I have loved all. I love Gospel Music, Classical Music, Bible Reading, Devotion Reading, Teaching, Gardening, Walking and Biking. I love time with my wife and time with our adult children and their children. I am relational and love to connect with people. I live in Simsbury CT with my wife and with our Schnauzer Jesse - we moved here from New Haven CT to be next door to our grandkids and their parents - to participate in their care and their life daily. We are setting into a small village within Simsbury, which is wonderful. I often ponder life and living and often consider life from the perspective of relationships and sharing and caring. I aim to be faithful to my Call as Servant-Physician, Husband, Father, Grandpa, and Disciple of Jesus Christ. "


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Care Philosophy

This content was provided by Dr. Mahnensmith "? I have had a wonderful professional journey - Helping people, serving causes, serving people. Feedback has been positive - commending- and collegial. Peer Reviews uniformly excellent. My work centers on each Person. I have loved serving people and their needs. I view Health Care Service as a special Privilege - as a Calling. I aim to be Faithful to this Special Calling - Respectful of All - To be a means of Care and Caring ? To Serve Others with no regard to compensation ? To not ever shun a person ? I will always consider their special circumstance and need ? I will be Careful, Cautious, while being Comprehensive and Diligent - Providing Care with Caring, Commitment, Respect and Dignity, Minimizing Risk and Harm. Conferring Caring and Value to each Person, Conferring Personal Considerations with Shared Decision Making ? To Always Consider the Public Health Contexts and Concerns. I practice and teach Thru Pathways and Guidelines. I am committed to the Special Calling of the Physician"


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  • Internal Medicine
  • Diabetes Medicine
  • General Medical Practice
  • Nephrology & Hypertension

Board Certifications

  • Internal Medicine
    Accredited by: American Board of Internal Medicine*
  • Nephrology
    Accredited by: American Board of Internal Medicine*

Conditions Treated

  • Acidosis
  • Acute Glomerulonephritis
  • Acute Gout
  • Acute Kidney Failure
  • Adrenal Gland Diseases
  • Adrenal Insufficiency
  • Alkalosis
  • Anemia
  • Arthritis
  • Arthritis of the Ankle
  • Arthritis of the Finger
  • Arthritis of the Foot
  • Arthritis of the Hand
  • Arthritis of the Midfoot
  • Arthritis of the Neck
  • Arthritis of the Shoulder
  • Arthritis of the Spine
  • Arthritis of the Toe
  • Arthritis of the Wrist
  • Asthma
  • Atherosclerosis
  • Bone Disorders
  • Calcium Metabolism Disorders
  • Cancer
  • Carotid Atherosclerosis
  • Chronic Anemia
  • Chronic Glomerulonephritis
  • Chronic Kidney Diseases
  • Congenital Renal Agenesis and Dysgenesis
  • Coronary Artery Disease (CAD)
  • Crystal Arthropathy
  • Deficiency-Induced Osteoporosis
  • Dehydration
  • Diabetes
  • Diabetes Insipidus, Nephrogenic
  • Diabetes Mellitus, Secondary
  • Diabetes Type 2
  • Diabetes With Renal Manifestations
  • Diabetic Ketoacidosis
  • Diabetic Retinopathy
  • Disuse Osteoporosis
  • Drug-Induced Osteoporosis
  • End-Stage Renal Disease
  • Familial Combined Hyperlipidemia
  • Familial Hypercholesterolemia
  • Goiter
  • Gout
  • Hepatorenal Syndrome
  • Hydronephrosis
  • Hypercalcemia
  • Hypercholesterolemia, Autosomal Dominant
  • Hypercholesterolemia, Autosomal Recessive
  • Hyperkalemia
  • Hyperlipidemia
  • Hyperparathyroidism
  • Hypertension
  • Hypertensive Chronic Kidney Disease
  • Hypertensive Heart Disease
  • Hypertensive Heart and Chronic Kidney Disease
  • Hypokalemia
  • Hypoparathyroidism
  • Hyposmolality and Hyponatremia
  • Hypotension (Excluding Maternal)
  • Hypothyroidism
  • Idiopathic Osteoporosis
  • Iron Deficiency Anemia
  • Kidney Disease
  • Kidney Infection, Acute
  • Kidney Stones
  • Limb Swelling Caused by Fluid Overload
  • Lipid Disorders
  • Magnesium Metabolism Disorders
  • Malaise and Fatigue
  • Menopause
  • Mineral Metabolism Disorders
  • Nephritis and Nephropathy
  • Nephrotic Syndrome
  • Nutritional Anemia
  • Obesity
  • Osteoporosis
  • Overweight
  • Pernicious Anemia
  • Phosphorus Metabolism Disorders
  • Postmenopausal Osteoporosis
  • Primary Hyperparathyroidism
  • Primary Osteoporosis
  • Proteinuria
  • Renal Artery Arteriosclerotic Disease
  • Renal Hyperparathyroidism
  • Renal Osteodystrophy
  • Retina Diseases
  • Secondary Hyperparathyroidism
  • Secondary Osteoporosis
  • Secondary Renovascular Hypertension
  • Senile Osteoporosis
  • Symptomatic Menopause
  • Thyroid Cyst
  • Thyroid Disease
  • Transient Osteoporosis of Hip
  • Vitamin D Deficiency
  • Wegener's Granulomatosis


Read More


  • Abdominal Paracentesis
  • Abscess Incision and Drainage
  • Arteriovenostomy for Renal Dialysis
  • Electrocardiogram (EKG)
  • Hemodialysis
  • Injection Therapy
  • Injection of Tendon
  • Joint Injection
  • Kidney Stones Treatment
  • Percutaneous Biopsy of Autologous Kidney
  • Peritoneal Dialysis
  • Physical Examination
  • Renal Biopsy
  • Sacroiliac Joint Injection
  • Spirometry
  • Thoracentesis
  • Urinalysis

Background Check

0 Malpractice Claims

No malpractice history found for Connecticut.

0 Sanctions

No sanctions history found for the years that Healthgrades collects data.

0 Board Actions

No board actions found for the years that Healthgrades collects data.


  • Yale University
    Medical School | Graduated 1977
  • Yale New Haven Hosp-Yale U
    Internship Hospital | Completed 1978
  • Yale
    Residency Hospital | Completed 1981
  • Yale New Haven Hosp-Yale U
    Residency Hospital | Completed
  • Yale
    Fellowship Hospital | Completed 1984

Awards & Recognition

Awards & Honors
  • Healthgrades Honor Roll
Media & Publications

Dr. Mahnensmith has no media or publications listed.

Languages Spoken

  • English

Memberships & Professional Affiliations

Dr. Mahnensmith does not have any memberships or affiliations listed. If you are Dr. Mahnensmith and would like to add memberships or affiliations, please update your profile.

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Now Accepting New Patients
This provider offers the following appointment availability:
Same Day
Next Day
Dr. Mahnensmith accepts 10 insurance carriers
  • Aetna
    Choice Plus POS II
  • Anthem
    Pathway X Ind PPO Direct Access CT
  • Blue Cross Blue Shield
    Blue Card PPO
  • Blue Cross Blue Shield of Louisiana
    BlueConnect HMO
  • Blue Cross Blue Shield of Massachusetts
    Preferred Blue PPO
  • Cigna
    Cigna HMO
    Cigna PPO
    Open Access Plus
  • EmblemHealth
    Health Insurance Plan of Greater New York (HIP) PPO
  • Harvard Pilgrim Health Care
    Harvard Pilgrim Health Care PPO
  • Oxford Health Plans
    Freedom Plan
  • UnitedHealthCare
    Oxford Liberty

*Please verify this information when scheduling an appointment.

Hospitals where Dr. Mahnensmith has admitting privileges

Yale - New Haven Hospital
20 York St
New Haven, CT 06510
View Hospital Profile

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