It said current levels of unfilled orders are at 45 days' sales.
At the end of the last quarter, the company had almost $1 billion in unfilled orders.
Despite these efforts, the Mint was forced to return many orders unfilled.
Unfilled orders are a widely followed predictor of general business conditions.
Unfilled orders fell 1.1 percent in June, the fourth straight decline.
"As these unfilled orders continue to slide, it doesn't look good for future production and hiring."
Unfilled orders for it totaled 15,580 on April 30, 1934.
And for the 10th straight month unfilled orders fell.
But the decline in unfilled orders, to $491.4 billion, was the third in three months.
Deliveries of the type totaled 121 with no unfilled orders.