U.S. Sen. Lisa Murkowski's office, in a release, said the funding was included in a $1.1 trillion spending plan that passed last weekend.
Murkowski spokesman Matthew Felling said the funding will help with field preparations for the new interceptors that will be added, including helping to restore a previously mothballed missile field.
On Friday, Murkowski's office said a separate defense authorization bill called for $40 million for improvements to and expansion of the missile defense system at Fort Greely. Felling told The Associated Press on Tuesday that was a recommended amount that appropriators decided should be $50 million instead. That $50 million is reflected in the spending bill.
"This increased funding between the authorizers and the appropriators demonstrates the high priority that the nation is placing on our missile defense given international dynamics, in addition to increased confidence after this summer's successful test and Congress taking a lower 48 site out of consideration," Felling said in an emailed statement.
The defense bill blocked funding for consideration of an East Coast missile site, Murkowski's office said.