I am a results-oriented, energetic advocate for my clients. I am passionate about representing my clients. As most cases come from word-of-mouth referrals, I am proud of my reputation built one client at a time. Most clients are faced with a difficult challenge in a critical part of their lives: their jobs and careers. I am competitive and look forward to taking the fight to the employer to redress unfair and illegal actions. I align our firm's fee arrangement with the client's desired outcome so that there is an identity of interest in the result sought. My success is defined by each client obtaining the desired outcome as a consequence of my effective counsel. Most of all, I love what I do, and that is helping people and seeking fair results for clients who deserve better treatment from their employers.
5
Practice Areas
37 years | 5,000 cases
37 years | 200 cases
37 years | 400 cases
37 years | 500 cases
33%-40%
State: New Jersey
Acquired: 1989
No misconduct found
State: New York
Acquired: 1989
No misconduct found
State: District of Columbia
Acquired: 1991
No misconduct found
177 Client Reviews
Showing 1 - 5 of 19 reviews | Trustworthiness
Posted by anonymous | February 13, 2026 | Hired Attorney | Lawsuits & Disputes
Jonathan Sack is the “real deal”
Jonathan Sack actually listened to us. He took the time to understand the inequity of our situation. He was the person calling and emailing us in between huge case trials to give us advice. His advice was on point. We had other attorneys shy away from the big bank employee name but Jonathon rose ...
Posted by anonymous | April 28, 2023 | Hired Attorney
My Trusted Advisor
An incredible mind and top subject matter expert. A quick read and study. Focused on doing the right thing for his clients at all times, regardless of time of day. Built up trust in an instant, was my guiding light at my darkest moment and kept me grounded and focused. No question was a hard ques...
Posted by anonymous | September 22, 2022 | Divorce & Separation
Knowledgeable and Responsive
A contact and previous client referred me to Jonathan Sack. I had a complex separation agreement. Jonathan reviewed the agreement in detail, advised me on my options, and took the time to walk me through everything and answered all my questions. Prior to connecting with Jonathan, the ambiguity and co...
Posted by anonymous | March 14, 2022 | Hired Attorney | Employment & Labor
Helped me out when I really needed it
I was suddenly let go from my job under shady circumstances, and I was so scared of my company that I wanted someone to make sure that it was actually in my best interest to sign their release and accept their severance. I called several attorneys and they all wanted hundreds of dollars to read m...
Posted by anonymous | March 02, 2022 | Hired Attorney
Great Lawyer
Jonathan provided great legal advice and explained all aspects of the situation to me. He was transparent and responsive to all my questions. He delivered on what he promised and exceeded my expectations. I would highly recommend him to anyone who needs excellent legal advice.
"Jonathan is one of the most professional, effective, and direct attorneys I have ever met. His knowledge of labor and employment law is vast and very respected. You can't go wrong having him on your team."
No Endorsement Data Available Yet
This attorney hasn't created any attorney endorsements recently on Avvo.
2025
Super Lawyer, Super Lawyers
2024
Super Lawyer, Super Lawyers
2024
Client's Choice, Avvo
2023
Super Lawyer, Super Lawyers
2017
Super Lawyer, Super Lawyers
1986
Dewey Scholarship, Dewey Scholarship
1989 - Present
Partner, Sack & Sack, LLP
1989 - Present
New York State Bar Association
1989
JD - Juris Doctor
1986
BA - Bachelor of Arts
English