Doctors Igor Borisov, MD and Daniel Witten, MD FACP along with the medical office team at Ninth Avenue Internal Medicine provide comprehensive and compassionate primary care to patients of Denver Metro Area. Since 2003, they offer a full scope of medical services, including yearly physicals, annual vaccinations, management of acute and chronic medical conditions such as diabetes, hypertension and heart disease, thyroid and endocrine conditions, COPD and asthma, or anxiety and depression. EKG, spirometry, swabs, peripheral arteries disease testing is readily available and finger stick or on site labs can be drawn during the appointments. 

The doctors routinely screen patients for a wide range of chronic conditions, including high cholesterol, early heart disease, diabetes, sexually transmitted infections, digestive diseases, attention deficit disorder, insomnia and more. Flu, shingles, pneumonia, tetanus, hepatitis and other vaccines are also available. We were also awarded the Civil Surgeon designation by the USCIS and perform the immigration exams and vaccinations. 

Preventive medicine is a high priority for the physicians at Ninth Avenue Internal Medicine, to catch signs and symptoms of chronic diseases and help patients feel better. We care deeply about our patients and their families, value their lifestyle and time and understand the economic and social impacts of the illnesses. We make our best to ensure our patients understand the treatment plan and form the long term treatment goals. 

Ninth Avenue Internal Medicine accepts most insurance, works with the wide range of outstanding specialists all over Denver Metro Area. Same-day appointments are also available. If you are seeking medical care to prevent or manage an acute or chronic health condition, call our office or book an appointment online today.



Some restrictions apply.

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Words from our patients

  • Google

    "Good, clean office, with friendly and caring staff. Have been to both doctors, Dr. Witten and Dr. Borisov are both very educated and caring."

    Verified Patient
  • Google

    "It's been over 10 years both me and my wife have been seeing Dr Witten. [...]been there for many ups and downs and we recommend them to anyone."

    John W.
  • Google

    "I would highly recommend this office for any and all internal medicine needs. They are efficient, professional and manage to have a great sense of humor."

    Scott M.
  • Yelp

    "I see Dr. Witten, and he is my favorite doctor ever. I feel so comfortable when I'm talking with him, and I can be honest and know he's not judging me."

    Angela A.
  • Yelp

    "As much as I don't like being sick, these guys were awesome and made me feel a lot better. I switched from my old doctor to them that week."

    R. A.


Accepted insurance plans:

Anthem BCBS
Assurant Health
Celtic Insurance Company
CNIC Health Solutions
Continental Benefits
First Health
Freedom Life
GWH-Cigna (formerly Great West Healthcare)
Health Net
Mail Handlers
Meritain Health


Ninth Avenue Internal Medicine
4500 East 9th Avenue, Suite 140
Denver, CO 80220
Phone: 303-394-2152
Fax: (303) 394-2496

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