On February 11, 2021, in Cargo Systems Messaging Service (CSMS) #46189077, U.S. Customs and Border Protection (CBP) clarified the document requirements for commercial shipments imported under 9808.00.30. This subheading allows for duty-free treatment on imports for military departments.
A duty-free certificate from the Defense Contract Management Agency (DCMA) is required to be submitted via the Document Image System (DIS) “within six months from the date of entry or release under the immediate delivery release procedures.” If the duty-free certificate is not submitted within the required timeframe, the entry will be liquidated “dutiable with the applicable HTS.”
CSMS #46189077 can be found here:
https://content.govdelivery.com/bulletins/gd/USDHSCBP-2c0ca15?wgt_ref=USDHSCBP_WIDGET_2