Mountainside Medical Group
Internal Medicine • Montclair, NJ
Information from public sources; not independently verified. Confirm hours, insurance and appointment availability with the clinic.
Last gathered July 11, 2026. How our information is sourced · Report incorrect information
About
Mountainside Medical Group - Primary Care is an internal medicine clinic located at 239 Claremont Ave., Suite A, in Montclair, NJ. The clinic offers primary care and internal medicine services, with hours Monday through Friday from 8:00 AM to 5:00 PM.
Services Offered
Insurance & Payment
Not published.
Languages Spoken
FAQs
What are the hours of operation?
Monday through Friday 8:00 AM – 5:00 PM.
What is the address for Mountainside Medical Group – Primary Care?
239 Claremont Ave., Suite A, Montclair, NJ 07042.
What is the phone number?
(973) 338-4900.
Social Media
Photos
Photos published by Mountainside Medical Group showing the internal medicine practice in Montclair, NJ.
What Patients Say
Overall sentiment across review platforms: mixed
- Hackensack Meridian Mountainside Medical Center Find a Provider portal: 4.7 to 5.0 stars (varies by provider) (Multiple individual provider ratings ranging from 39 to 936 reviews)
- Birdeye (Internal Medicine): 4.7 stars (15 reviews)
Patients praise
- High star ratings for individual providers on internal portals
- Some experiences noted as quick and pleasant
- Helpful and kind staff in some specific locations
- Positive experiences reported with medical care and nursing staff in specific units
Common complaints
- Long wait times for appointments and during office visits
- Unprofessional or dismissive customer service/staff interactions
- Difficulty with administrative processes such as check-ins and scheduling
"I have to tell never have I ever dealt with a receptionist who thought they were a physician... There should only be scheduling not discussion of whether the patient is correct or not. TERRIBLE!!!!!!!!"
- Birdeye Review"Waited months to get a new patient appointment. Took a half day at work and waited an hour to find out that the receptionist had not checked me in properly..."
- Yelp Review"The staff is helpful and kind. The office staff was good about making sure I was seen close to my actual appointment time..."
- Yelp ReviewSynthesized from public review platforms as of Jul 11, 2026 - sources: [1][2][3][4].
In the News
- Mountainside Medical Group - Primary Care - Jan 29, 2026
- Mountainside Medical Group - Primary Care - Oct 14, 2025
- Hackensack Meridian Mountainside Medical Group Welcomes Hanna Carrasco, D.O. - Hackensack Meridian Mountainside Medical Center - Jan 13, 2026
- Hackensack Meridian Mountainside Medical Group Welcomes Hanna Carrasco D.O. | Newswise - Jan 15, 2026
Information sourced from the clinic's website as of July 11, 2026.
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