The Tax Act was signed by President Trump December 22, 2017. Most provisions in this tax act are temporary beginning December 31, 2017, and ending on or before January 1, 2026.  Basically, eight years.  In 2026, they will revert back to what we had in 2017. 

There are some items that are permanent in this tax act. 

1. Index and inflation. To change from using the Department of Labor's CPI-U method to the chained CPI-U method to measure inflation for taxable years beginning December 31, 2018, is permanent. 
2. Healthcare's individual mandate, reducing the penalty to zero for individuals without minimum essential coverage for months beginning after December 31, 2018, is permanent.
3. Alimony.  Payment of alimony is not deductible and receipt of alimony is not includible in gross income for divorce or separation instrument executed after December 31, 2018. 
4. Discharge of student loans.  Debt forgiveness of certain student loans not includable in gross income for loans discharged after December 31, 2017. 

There are modifications to the income tax brackets with the highest rate of 37% reduced from 39.6%.  Basically, the 32% tax rate over $315,000, but not more than $415,000 comes into play with some of the tax act dealing with phase-out. 

There is an observation that the 3.8% tax on net investment income results in a new top-margin income tax rate of 40.8%.  All the additional taxes that are part of the Obamacare has not changed and will not change until it is overturned.