The period in summer of 2017 would have been more amenable to tax reform than the current climate at the end of 2017 and most of 2018.  Looking over charts, the next period that looks possible is December of 2018 - there is no other configuration suggesting successful tax policy before then. 

What comes about in December of 2018 is not likely to be tax reform in the conventional sense, it would simply be policy based on less revenue (Transiting Saturn moves into USA's 2nd house of income).  

As already noted, State taxes are likely going to be impacted under this policy (Trasniting Pluto square-adverse USA's Mars). 

Special interests will be able to get deals cut (Transiting South node in conjunction-emphasis with USA's Pluto) suggesting behind the scenes activity.

With revenue down, assume that debt will be going up (Transiting North Node in inconjunct-break and adjust angle to USA's Moon).