Mario J. DeRossi

Mario J. DeRossi

also known as DeRossi Law Firm, LLC

4.9
Rating: 10.0

Licensed for 24 years

Divorce and separation Lawyer at Mineola, NY
Practice Areas: Divorce & Separation, Family, Child Custody, Child Support

100 Old Country Road, Suite 301, Mineola, NY

About Mario

Biography

Fees and Rates

We have not found any cost information for this lawyer


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Licenses

Licensed in New York for 24 years

State: New York

Acquired: 2001

Currently Registered

No misconduct found

Licensed in Massachusetts for 24 years

State: Massachusetts

Acquired: 2001

Inactive

No misconduct found

Location

DeRossi Law Firm LLC

100 Old Country Road, Suite 301, Mineola, NY, 11501

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Mario J. DeRossi's Reviews

Avvo Review Score

4.9 /5.0

113 Client Reviews

Showing 1 - 5 of 35 reviews | General Knowledge

Posted by Stephen | August 02, 2024 | Hired Attorney | Divorce & Separation

Stephen Cowden

I was referred to Mario by a friend of mine, and from the moment I contacted him I could see that he’d be very easy to deal with and very professional. He showed me that what I’m going through many people have gone through before and that even though this is an emotional process, that will get thr...ough it together, and he was absolutely correct. He instilled confidence from day one is able to bring me through step-by-step. he explained the law and easy to understand manner. I was always able to reach Mario or someone at his office would get back to me in a very timely manner and he would let me know when our communication would have to be in person by phone rather than email. I would highly recommend Mario without reservation as he made a very difficult process seem relatively easy and I got through a very contentious divorce and resolution with his expertise.

Posted by anonymous | January 27, 2023 | Hired Attorney | Divorce & Separation

Mario, a truly dedicated attorney

Mario was a referral from a close friend. I was starting the predivorce process and desperately need some sound advice. I called Mario and explained my horrendous scenario. Mario asked if he might review my 30 page prenuptial. After reading the document, Mario shared his review. I might add, I had... not hired him as of yet and he volunteered to read my entire prenuptial. This attorney who I really didn't know, spent a lot of time reading my document and talking with me on the phone. I remember the call was almost one hour. I was impressed, to say the least. I moved forward with hiring Mario as my divorce attorney. He was very patient, clear in his communication and listened to all I had to say. We worked together as a team. I contributed my thoughts along the way. Mario was always open-minded as the divorce continued. I was provided with how the court system worked along with the various episodes that might occur. My first time in court was stressful for me. Mario helped me to relax and stay on the path we had set up. With support and preparation from Mario, my future meetings went smoothly. My divorce is soon to be final. I thank Mario for his knowledge and expertise, plus I thank his office staff and Nicole. They were always pleasant, accountable and available. I found Mario to be very dedicated in assisting me with my divorce. I highly recommend him to anyone looking for a divorce attorney.

Posted by anonymous | December 01, 2022 | Hired Attorney | Family

dishonest and careless

Mario represented me in family court over a period of over 2 years. While he comes across as confident and certain of himself, his work product is sloppy and harmful. Examples: -showing up to financial hearing without an FDA -telling me that it is fine to only pay what you can for child supp...ort, "the court will understand." This advice almost landed me in jail. -claiming to have done discovery of finances of the other party yet never sharing the product of that discovery, and not saving it in the files. when asked about this, he simply didn't answer. -accepting service of important papers on my behalf, without my consent, and not sharing them with me. I found out about them when I got the files back after letting him go, over a year after he accepted service. -the papers that he kept in my file was incomplete, like, less than half of what should be by law and by retainer agreement. -refusing to call out other lawyers and/or judges/magistrates for not following due process or for unethical behavior (something lawyers are ethically bound to do). -coercing me to sign a stipulation with so many holes in it that it is basically meaningless and almost unenforceable. it has cost me many thousands of dollars to attempt to rectify the stip he drew up last minute. -when he would give me one of his certain and authoritative answers or advice, and then later hearing him give the exact opposite advice, if I would call him out on this he would become extremely slippery and dishonest. In fact, he once told me with pride that he's "not a lawyer, but a liar." -submitting papers on my behalf without first letting me see what he was submitting. -failing to request counsel fees, multiple times, when I requested he do so. His response was "you seek counsel fees at any time." It's not that simple. At all. -He responded to emails quickly, but often in a way that showed he did not understand what was being asked, and did not make sure his own messages were clear and understandable. Often they were extremely vague, and he would simply not respond at all to certain questions, with no explanation of why. He'd just ghost them. -the list could go on a lot longer. The short message is, I absolutely would not recommend hiring Mario, unless you have enough money to flush down the toilet and care not about the issue you are hiring him for. If you care about your child, and are dealing with a mother that doesn't want their child to have a father, I do not recommend hiring him. I find all the 5 star ratings here very suspicious. If you read them, you'll see most of them write barely a sentence.

Posted by anonymous | October 03, 2022 | Hired Attorney | Divorce & Separation

Shark with a Heart

A mom at school asked if I had a divorce lawyer yet. I was heavily leaning toward using someone else at the time. She went on to say her divorce lawyer wasn't very good but that her husband's was a real shark. Oh, I'm so sorry, I said. And also, awkwardly, can I get your husband's lawyer's phone numb...er? That's how I came to meet Mario DeRossi. It was love at first zoom. He was knowledgeable, clear, and concise. He had a heart and the no nonsense attitude I knew I needed. As a mom, I thought long and hard about whether or not to divorce. I contemplated staying until our little daughter went to college. In the end, I decided I had to divorce. I was terrified of the custody portion. While I'm not rich, I'm a hard worker and can make more money, but the custody had me paralyzed. I didn't want our daughter to feel like a ping pong ball, etc. so, getting as much custody as possible was my top priority. And Mario succeeded! And with flying colors! He fought for me to gain primary physical custody. I came out better than I'd thought financially. I felt I had a true partner. Mario was on time and on top of things. He came to every call prepared. He answered every email - sometimes just a sentence - but there was always a reliable and informed answer. I could call and make an appointment whenever I wanted. He made himself available. Throughout this whole process Mario has been my secret weapon. When I felt nervous and anxious at night I would revisit our conversations. I remember telling him I was scared we'd have to do 50-50 custody since it seemed preferred by the court, according to Google. He told me I don't do 50-50, that's not how I roll. I would say that to myself over and over. The day of my trial Mario kept me abreast of everything from the moment I woke up. We ended up settling and it was magical - Mario jumped into action and finagled numbers around. He told me this was my life and he would fight for what I wanted and that this was my decision and only my decision. I told him to guide me. I could not be happier with the result. I now have primary physical custody - my top non-negotiable and ended up better than I expected financially. Additionally, Mario was super fair with his billing. I wasn't charged when he read my emails etc (I also was mindful of how much I emailed). I've since recommended Mario to another mom. My whole focus was on our daughter and Mario just got it. He's like your smart friend - the one that's super cool and you love hanging out with but is very busy so you meet while you can and ask everything you can think of. I love Mario. I'm actually sad I don't have to talk with him anymore. But I'm glad to be onto my next chapter. I highly recommend Mario DeRossi. Hiring him to represent me in my divorce was the best decision I made.

Posted by Michael | April 29, 2022 | Hired Attorney | Family

You will be in good hands.

I have had a fair amount of legal dealings in business and consider myself a relatively logical independent person. The dynamics of family law feel much different to me, there are emotions involved, decisions are complicated, compromise is often inevitable, and the results have a material impact on ...many lives. The best course of action is not always clear, it can be painful, it can be confusing, even to a logical and rational thinker. You need guidance from someone who understands and has a feel for the law. From my experience in the past year, Mario has a special talent for practical strategy and keeping things on course. All while respecting the factors that are most important to you. Mario always knows the answer, whether it be a technical legal question or more importantly, what to do at complicated decision points.

See All Client Reviews

Mario J. DeRossi's Lawyer Endorsements

Endorse Mario
Michael Robert Gionesi headshot
Michael Gionesi

Divorce and separation lawyer | Sep 17

Relationship: Fellow lawyer in community

"A powerful and zealous advocate for his clients, Mario has earned the respect of his peers and the judiciary. His level of civility is second to none, which makes him an even more effective advocate. His effectiveness is surpassed only by his keen intellect. I wholeheartedly endorse him."

Michael Drew DiFalco headshot
Michael DiFalco

Divorce and separation lawyer | Sep 19

Relationship: Opposing Counsel on matter

"I endorse this lawyer. Mario is an excellent attorney. We've had a couple of cases together and he's a zealous advocate for his clients while remaining a gentleman."

Somair Syed Alam headshot
Somair Alam

Divorce and separation lawyer | Feb 13

Relationship: Fellow lawyer in community

"Exceptional attorney, dedicated to client success. Highly recommended."

Joshua Bradley Hecht headshot
Joshua Hecht

Divorce and separation lawyer | Oct 02

Relationship: Fellow lawyer in community

"Mario is an exceptional attorney. His knowledge of family law matters is impressively extensive, but more importantly she has a deep focus on the needs of her clients. Highly recommended!"

Barry J. Gross headshot
Barry Gross

Divorce and separation lawyer | Jan 22

Relationship: Opposing Counsel on matter

"I endorse this lawyer. Mr. DeRossi is an extremely talented and knowledgeable attorney. He is "old school" in that his word is his bond."

Frederick William Vasselman headshot
Frederick Vasselman

Divorce and separation lawyer | May 29

Relationship: Worked for lawyer

"I endorse this lawyer."

Susan Ann Kassel headshot
Susan Kassel

Divorce and separation lawyer | May 17

Relationship: Opposing Counsel on matter

"I endorse this lawyer. Mario is always well prepared, clever and quick on his feet. He is an excellent attorney."

John M O'Brien headshot
John O'Brien

Commercial real estate lawyer | May 14

Relationship: Fellow lawyer in community

"A truly excellent attorney well respected in the legal community. I wholeheartedly recommend him to anyone looking for a lawyer who knows the law and truly cares about protecting the rights of his clients and getting them the most favorable result possible."

Christopher Daniel Leroi headshot
Christopher Leroi

Divorce and separation lawyer | Sep 15

Relationship: Fellow lawyer in community

"Mr. DeRossi is an outstanding attorney who provides exemplary advice on Avvo. I would recommend everyone and anyone to him for representation. Even though I have been practicing fo 24 years, as a judge, magistrate, prosecutors, and in private practice, I learn valuable new information from him every day. A superb attorney."

Howard M Lewis headshot
Howard Lewis

Divorce and separation lawyer | Jun 09

Relationship: Fellow lawyer in community

"I endorse this lawyer. Attorney DeRossi is an outstanding attorney with an exceptional reputation. He is a strong and zealous advocate for his clients and a credit to the legal profession. I highly recommend his legal services."

Ivan E. Young headshot
Ivan Young

Divorce and separation lawyer | Apr 10

Relationship: Fellow lawyer in community

"Having known Mario for a few years now, I can firmly state that he is a gifted attorney that advocates for his Client's in a manner rivaled by few. Not only does Mario have a profound knowledge of the law, but he truly is personable and attentive to his Clients which gives all those that go to him a genuine sense of comfort in such a stressful situation. I would and do recommend Mario to all Clients seeking representation in matrimonial related issues."

Jason Adam Isaacson headshot
Jason Isaacson

Divorce and separation lawyer | Oct 11

Relationship: Opposing Counsel on matter

"A strong advocate and always professional, Mr. DeRossi is an experienced attorney who offers practical solutions to resolve difficult issues."

Robert Scott Grossman headshot
Robert Grossman

Family lawyer | Jun 21

Relationship: Opposing Counsel on matter

"Mario and i were adversaries in a contested matrimonial case. I found him to be knowledgeable, a true professional, and most importantly, a man of his word."

Matthew Scott Seidner headshot
Matthew Seidner

Family lawyer | Mar 20

Relationship: Fellow lawyer in community

"Mr. DeRossi has an excellent reputation not only among other attorneys but before the bench. It is a privilege to consider him a colleague in an area of law that requires not only intelligence but compassion and patience."

Jill Altarac headshot
Jill Altarac

Divorce and separation lawyer | Nov 14

Relationship: Opposing Counsel on matter

"I have had several matters with Mr. DeRossi, and he is a strong advocate for his clients. Mr. DeRossi is very professional and works diligently to assist his clients achieve their intended results."

Caitlin Donahue headshot
Caitlin Donahue

Family lawyer | Aug 16

Relationship: Opposing Counsel on matter

"Mr. DeRossi displays an impressive level of professionalism and integrity while representing his clients. Not only does he have an obvious command of the law, but also places a high priority on maintaining the trust of opposing counsel."

Christian Aaron Pickney headshot
Christian Pickney

Divorce and separation lawyer | Aug 28

Relationship: Opposing Counsel on matter

"In a divorce case I handled against Mr. Derossi he represented his client zeaolously and professionally. He protected his client's rights and did not engage in unnecessary litigation that would have wasted our client's money and time. He knows the law and conducts himelf professionally. It was my privilege to work with this attorney."

Brian C. Pascale headshot
Brian Pascale

Personal injury lawyer | Aug 05

Relationship: Worked together on matter

"I endorse this lawyer's work. He is an amazing, detail oriented, and professional litigator."

Joseph DiBenedetto headshot
Joseph DiBenedetto

Divorce and separation lawyer | Apr 30

Relationship: Worked together on matter

"I endorse this lawyer's work. Mario is very competent and considerate of his client's needs. Mario has repeatedly obtained exceptional results for his clients."

View All Endorsements
Joseph Steven Dujmic Jr. headshot
Joseph Dujmic

Divorce and separation lawyer

Michael Robert Gionesi headshot
Michael Gionesi

Divorce and separation lawyer

Lawrence Bruce LaRaus headshot
Lawrence LaRaus

Divorce and separation lawyer

Michael Drew DiFalco headshot
Michael DiFalco

Divorce and separation lawyer

Joshua Bradley Hecht headshot
Joshua Hecht

Divorce and separation lawyer

Barry J. Gross headshot
Barry Gross

Divorce and separation lawyer

Frederick William Vasselman headshot
Frederick Vasselman

Divorce and separation lawyer

Howard M Lewis headshot
Howard Lewis

Divorce and separation lawyer

Karina Alomar headshot
Karina Alomar

Divorce and separation lawyer

Ivan E. Young headshot
Ivan Young

Foreclosure lawyer

Kenneth John Ready headshot
Kenneth Ready

Personal injury lawyer

Jason Adam Isaacson headshot
Jason Isaacson

Divorce and separation lawyer

Matthew Scott Seidner headshot
Matthew Seidner

Divorce and separation lawyer

Jill Altarac headshot
Jill Altarac

Divorce and separation lawyer

Caitlin Donahue headshot
Caitlin Donahue

Family lawyer

Christian Aaron Pickney headshot
Christian Pickney

Divorce and separation lawyer

Joseph DiBenedetto headshot
Joseph DiBenedetto

Criminal defense lawyer

Brian C. Pascale headshot
Brian Pascale

Personal injury lawyer

Experience

Rating:  10.0 (Superb)

Honors

2025

Super Lawyer, Super Lawyers

2024

Super Lawyer, Super Lawyers

2023

Super Lawyer, Super Lawyers

2022

Super Lawyer, Super Lawyers

2021

Super Lawyer, Super Lawyers

2020

Super Lawyer, Super Lawyers

2019

Super Lawyer, Super Lawyers

2018

Super Lawyer, Super Lawyers

2017

Super Lawyer, Super Lawyers

2016

Rising Star, Super Lawyers

2015

Rising Star, Super Lawyers

2014

Top 40 Under 40, The National Trial Lawyers

2014

2014 New York Metro Rising Stars, SuperLawyers

2014

Top Ten Ranking, The National Academy of Family Law Attorneys

2014

Top 40 Lawyer Under 40, The American Society of Legal Advocates

2014

Rising Star, Super Lawyers

2004

Award for Trial Advocacy, The Association of the Bar of the City of New York

2003

Army Commendation Medal, Trial Defense Service, United States Army

2003

Bronze Star Medal, Fourth Infantry Division, United States Army

2002

Army Commendation Medal, Fourth Infantry Division, United States Army

Work Experience

2009 - Present

Partner, Stern & DeRossi, LLP

2006 - 2009

Associate, Stern, Adler & Associates, LLP

2002 - 2006

Judge Advocate, United States Army

Associations

2014 - Present

The National Academy of Family Law Attorneys

Member

2014 - Present

The American Society of Legal Advocates

Me

2009 - Present

Nassau County Bar Association

Member

2009 - Present

New York State Bar Association, Family Law Section

Member

2009 - Present

Columbian Lawyers Association

Member

Education

2001

Saint John's University, School of Law

Juris Doctor

Languages

English

Activity

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Avvo Rating Levels
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