The dollar touched 14-month lows Thursday, while the euro hit the $1.17 mark as the FOMC held on policy.
The Fed noted that inflation remains below target, leading to the view it will remain cautious about further tightening.
The Fed also said it expects to start unwinding its balance sheet “relatively soon.”
The euro hit a high for the session of $1.1777, levels last seen in January 2015.
The single currency was off 0.01% at $1.1736. The pound held above the $1.31 mark.
The dollar remained weak against the yen at the 111 level.
The Aussie traded above $0.80 at levels last seen in May 2015.