Cohen, now a vocal Trump critic, said the real estate company stopped paying his bills after he began cooperating with several investigations.
In a 5-0 decision, the Appellate Division in Manhattan said a trial judge erred in dismissing Cohen's lawsuit.
The court said it was unclear whether Cohen's legal fees mounted because he had been a Trump Organization employee, which would entitle him to reimbursement.
The fees kept growing, and the Trump Organization has paid some of them, court papers show.
Michael Cohen and Justice Cohen are not related.