In an unexpected move (although all-too-commonfor an increasingly erratic agency), the USCIS will no longer accept Premium ProcessingService (PPS) for all H-1Bs, except for H-1B extensions with the same employeror H-1Bs for cap-exempt institutions, such as Universities or research organizations.

Effective September 11, 2018, PPSwill not be available for H-1B cap petitions and H-1B amendments.  The ban on PPS will continue until February19, 2019. 
The justification for the ban onPPS is to reduce overall H-1B processing times.  

If you are asking yourself how eliminating a fee-based premiumprocessing service will reduce processing times, you are not alone.  The PPS is supposed to pay for itself.  This is yet another example of an agency thatcannot get out of its own way.