An Ossining law firm is demanding restitution from a tax preparation service it claims failed to file 2024 state and federal tax returns or secure a $35,000 tax refund.
The Steiner Law Firm accused AG Tax Services of fraud, in a complaint filed on Dec. 8 in Westchester Supreme Court.

AG Tax Services and owner Michael Grossbach “engaged in a systematic scheme of deception,” the complaint states, “by repeatedly and falsely representing … that all required business and personal tax returns had been timely filed.”
The law firm and tax service are both based in Ossining, side-by-side in the same office building in Central Westchester Business Park.
Steiner Law is led by Norman Steiner. It specializes in personal injury cases, such as medical malpractice and car accidents, and its website boasts of more than $500 million in verdicts and settlements.
AG Tax Services describes itself as “artisans of accounting” that “paint the perfect, complete picture of your finances.”
Grossbach solicited Steiner to handle the law firm’s 2024 taxes, according to the complaint, and Steiner let Grossbach handle his personal taxes as well.
Grossbach allegedly advised Steiner that he would create a S-Corporation – a tax status that enables business owners to pay lower federal taxes – and get a tax refund of at least $35,000.
Grossbach repeatedly assured Steiner that all tax returns and paperwork had been filed on time, according to the complaint, but allegedly refused to provide proof of performance.
Then, after months of assurances, the complaint states, Grossbach belatedly admitted that Steiners’ and his wife Olga’s personal tax returns had not been filed.
Steiner claims that Grossbach abruptly ceased communications and cut off access to the AG Tax Services portal where tax records are stored. When Steiner protested, access was restored for 24 hours, according to the complaint, but the time was insufficient to retrieve everything.
Steiner says an independent investigation established that the IRS did not accept the business tax returns or the S-Corporation designation and that state and federal personal tax returns were not filed.
Grossbach and AG Tax Services engaged in fraud and deceit, the complaint states, “to collect fees for services they had no intention of properly performing or were incapable of properly performing.”
Steiner is demanding unspecified monetary damages to cover AG Tax Services’ fees, tax penalties and liabilities, loss of a refund, and new fees paid to correct the problems.
He also is demanding unspecified punitive damages, to “send a message that such fraudulent and malicious conduct will not be tolerated.”
Grossbach did not reply to a request for comment that was submitted through the AG Tax Services website.













