Section 321, 19 USC 1321 is the statute that describes de minimis. De minimis provides admission of articles free of duty and of any tax imposed on or by reason of importation, but the aggregate fair retail value in the country of shipment of articles imported by one person on one day and exempted from the payment of duty shall not exceed $800. The de minimis threshold was previously $200, but increased with the passage of the Trade Facilitation and Trade Enforcement Act (TFTEA).
The link below is to a one page document that provides a high level comparison between the two Section 321 Programs (Section 321 Data Pilot and the Entry Type 86 Test).
Section 321 Data Pilot
In this pilot, CBP is testing the utility of accepting advance data from e-commerce supply chain partners, including online marketplaces, for risk segmentation purposes.
Entry Type 86 Test
Deployed September 28, 2019, entry type 86 test is new entry type that is being introduced as a voluntary test. Entry type 86 test allows for entries that qualify for de minimis to be filed via Automated Broker Interface, including those subject to partner government agency data requirements for clearance.