Mountainside Medical Group - Primary Care
Internal Medicine • Montclair, NJ
Clinic Type
Internal Medicine
Address
239 Claremont Ave, Suite A, Montclair, NJ 07042
Phone
973-338-4900
ardentcustomerservice@ensemblehp.com
Opening Hours
Wednesday 8:00 AM – 5:00 PM; Thursday 8:00 AM – 5:00 PM; Friday 8:00 AM – 5:00 PM; (Hours shown in extracted text)
Website
https://mountainsidemedicalcenter.com/location/mountainsidemedicalgroupinternalmedicinemontclair/
Emergency Care
Emergency care available
Services Offered
Insurance & Payment
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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








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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