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 66 - 70 of 109 reviews | Employment & Labor
Posted by Mark | December 12, 2019 | Hired Attorney
Top Notch!
John is the guy you want in your corner. He is fast-working, aggressive and knows how to get the job done. He quickly resolved an HR issue I was unfairly involved with and delivered the outcome I was hoping for.
Posted by anonymous | December 04, 2019 | Hired Attorney
Severance and non-compete negotiation
I work in the hedge fund industry and hired Jonathan to negotiate the terms of my separation with my previous employer. Always responsive and generous with his time, Jonathan fought hard to get me better terms and dramatically reduced my non-compete time. He deals with the big names at every firm, an...
Posted by anonymous | November 18, 2019 | Hired Attorney
Severance
I was referred to Jonathan based on a friend's glowing recommendation. I highly recommend Jonathan. He was able to negotiate a severance package 7 times than which my employer originally offered. He was logical with his expectations of the outcome and supportive of what I was going through every step...
Posted by Elisabeth | October 30, 2019 | Hired Attorney
Elisabeth Halfpapp
He was very thorough, caring, and thoughtful. Helped me get through a tough negotiation with a plethora of support. Expert in individual employment law.
Posted by Rory | October 16, 2019 | Hired Attorney
Incredible!
Came to John with an employment contract that should’ve been used to wrap fish or start a fire. My employer had a permanent seat on the 9th ring of Dante’s hell . Jon and his team were outstanding. Always optimistic , supportive and very clear in managing my expectations. Made you feel like family . ...
"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."
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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