N.Y. Pers. Prop. Law § 48-C
If the assignor is not employed at the time he makes an assignment of future earnings, but is thereafter employed, his future earnings shall nevertheless become collectible by the assignee as provided in this article upon the filing of the prescribed documents with the employer. No assignment of future earnings shall become invalid by reason of the cessation of employment, or cessation of payment of earnings, but shall continue in effect, and may be applied to the payment of any future earnings from the same or other employment, in accordance with the provisions of this article, so long as the indebtedness secured by the assignment shall remain unpaid in whole or in part. If the assignor is re-employed by the same employer before the expiration of ninety days from the termination of employment, the assignment shall continue to be collectible without further filing of papers. If the employee is re-employed on or after the expiration of such ninety days, the assignment shall again become collectible from the employer as provided in section forty-eight-a only after copies of the assignment and the other documents specified in such section have been filed with the employer following the re-employment.
N.Y. Pers. Prop. Law § 48-C