Last week AmLaw 100 firm Polsinelli filed a federal lawsuit against a former partner Louis Mastriani. At issue is a client contingency fee of $1.5 million that the firm alleges Mastriani wrongly converted.
Mastriani joined Polsinelli in 2022, from AMS Trade. That firm, while no longer operating, was not dissolved as contingency fees previously earned were still being paid. In 2023 one of those clients moved its business to Polsinelli, with the understanding the contingency fees would now be paid to the new firm.
As reported by Law.com, the complaint alleges that’s not the way it went down:
This year, Mastriani led a favorable settlement agreement, and the client notified Mastriani that the entirety of the payment would be received by June 5 and that $1.5 million would be awarded to Polsinelli. However, Mastriani allegedly failed to disclose the payment information to Polsinelli management and instead falsely told the client that the money was to go to AMS in the fall—rather than immediately to Polsinelli, the complaint said.
And why did he allegedly do that? The complaint says, “Mastriani’s purported justification for this request was that ‘there is a strong possibility that I may be joining a new firm in a couple of months. If I do, the payment would be made to that firm, which I will then pass to me and my old firm [AMS].’”
But the client refused this financial arrangement and the fee was paid to Polsinelli. At that point it’s alleged Mastriani represented the fees as from prior work, and directed non-attorney staff members “to ‘process and transfer the funds to our AMS Trade account as you have done in the past.’”
A few weeks after this, Mastriani announced he was leaving Polsinelli and joining Buchanan Ingersoll & Rooney.
Mastriani has a very different take, naturally, and says the lawsuit “is the culmination of a campaign of ongoing vindictive retaliation in response to my departure from the firm, a departure prompted in large part by the greed and deceit of management.”
“The complaint and its supporting declaration are riddled with false statements, inaccuracies, and omissions of material fact, all of which are intended to gain funds from my former firm and me, to which Polsinelli has no legal or equitable entitlement,” Mastriani continued. “If Polsinelli wishes to air its baseless claims and dirty laundry in a public forum, then so be it, in which case I will vigorously defend and assert my own legitimate claims.”

Kathryn Rubino is a Senior Editor at Above the Law, host of The Jabot podcast, and co-host of Thinking Like A Lawyer. AtL tipsters are the best, so please connect with her. Feel free to email her with any tips, questions, or comments and follow her on Twitter @Kathryn1 or Mastodon @Kathryn1@mastodon.social.
The post Biglaw Firm Files Lawsuit Against Former Partner Over $1.5 Million Client Fee appeared first on Above the Law.

Last week AmLaw 100 firm Polsinelli filed a federal lawsuit against a former partner Louis Mastriani. At issue is a client contingency fee of $1.5 million that the firm alleges Mastriani wrongly converted.
Mastriani joined Polsinelli in 2022, from AMS Trade. That firm, while no longer operating, was not dissolved as contingency fees previously earned were still being paid. In 2023 one of those clients moved its business to Polsinelli, with the understanding the contingency fees would now be paid to the new firm.
As reported by Law.com, the complaint alleges that’s not the way it went down:
This year, Mastriani led a favorable settlement agreement, and the client notified Mastriani that the entirety of the payment would be received by June 5 and that $1.5 million would be awarded to Polsinelli. However, Mastriani allegedly failed to disclose the payment information to Polsinelli management and instead falsely told the client that the money was to go to AMS in the fall—rather than immediately to Polsinelli, the complaint said.
And why did he allegedly do that? The complaint says, “Mastriani’s purported justification for this request was that ‘there is a strong possibility that I may be joining a new firm in a couple of months. If I do, the payment would be made to that firm, which I will then pass to me and my old firm [AMS].’”
But the client refused this financial arrangement and the fee was paid to Polsinelli. At that point it’s alleged Mastriani represented the fees as from prior work, and directed non-attorney staff members “to ‘process and transfer the funds to our AMS Trade account as you have done in the past.’”
A few weeks after this, Mastriani announced he was leaving Polsinelli and joining Buchanan Ingersoll & Rooney.
Mastriani has a very different take, naturally, and says the lawsuit “is the culmination of a campaign of ongoing vindictive retaliation in response to my departure from the firm, a departure prompted in large part by the greed and deceit of management.”
“The complaint and its supporting declaration are riddled with false statements, inaccuracies, and omissions of material fact, all of which are intended to gain funds from my former firm and me, to which Polsinelli has no legal or equitable entitlement,” Mastriani continued. “If Polsinelli wishes to air its baseless claims and dirty laundry in a public forum, then so be it, in which case I will vigorously defend and assert my own legitimate claims.”

Kathryn Rubino is a Senior Editor at Above the Law, host of The Jabot podcast, and co-host of Thinking Like A Lawyer. AtL tipsters are the best, so please connect with her. Feel free to email her with any tips, questions, or comments and follow her on Twitter @Kathryn1 or Mastodon @[email protected].