Author: Arielle O’Shea, NerdWallet

At Fidelity Investments, which holds over 16.2 million 401(k) accounts, only 187,000 had balances of $1 million or more at the end of September.

A taxpayer who previously fell into the 15% tax bracket is now taxed at a 12% rate. Retirement investors can and should take advantage. Here’s how.