2016 New York Laws
LIE - Lien
Article 2 - (Lien) MECHANICS' LIENS
16 - Assignment of contracts and orders for public improvement to be filed.

  16. Assignment of contracts and orders for public improvement to be
  filed. No assignment of a contract for the performance of labor  or  the
  furnishing  of  materials  for a public improvement, or of the money, or
  any part thereof, due, or to become due, therefor, nor an order drawn by
  the contractor or sub-contractor upon the  public  corporation,  or  the
  head  of  the  department or bureau having charge of the construction or
  demolition of such public improvement, or the financial officer  of  the
  public  corporation, or other officer or person charged with the custody
  and disbursement of the corporate funds applicable to the  contract  for
  such public improvement, shall be valid unless such assignment or order,
  or  a  copy  thereof, be filed within twenty days after the date of such
  assignment of contract, or such assignment of money, or such order, with
  the head of the department or bureau having charge of such  construction
  or  demolition, and with the financial officer of the public corporation
  or other officer or person charged with the custody and disbursement  of
  the   corporate  funds  applicable  to  the  contract  for  such  public
  improvement, and such assignment or  order  shall  have  effect  and  be
  enforceable  from  the  time  of  such filing, and no such assignment or
  order shall have any validity until the same shall have been  so  filed,
  and  every such assignment or order, not filed, shall be absolutely void
  as against  a  subsequent  assignee  in  good  faith  and  for  valuable
  consideration,  whose  assignment  or  order  is  first  duly filed. The
  financial officer of the public corporation, or other officer or  person
  with  whom  the assignment order, or copy thereof, is filed, shall enter
  the facts relating to the same in the lien book or other  book  provided
  for such purpose.