ICE’s 287(g) active agreement data is a released as a snapshot — when agreements are added or removed, the updates are published as a completely new version of the Excel spreadsheet, available for download on the program landing page. This means each version of the spreadsheet lists the agreements active on the date it was published. There is no historical archive, so the ability to track changes requires reconstructing this metadata from saved snapshots.

We use a composite key (state + agency name + agreement type + signature date) to track agreements, but this is admittedly fragile. For example: when ICE corrects a typo in the agency name, there is no record of those changes on the published list, and our composite key is 'broken'.

Tracking for canceled agreements is only available for those removed from ICE's published list since December 8, 2025, as it requires intentional tracking to identify deleted rows from previous versions of the official list.

Some municipality population values may show as "NOT FOUND", where Census ACS data can't be reliably matched, or the jurisdiction covered by the agreement is not clear. This is the case for almost all of the Constable Officers participating (primarily in Pennsylvania, Tennessee, and Texas), which typically cover a segment of the larger county (and, therefore, listed by ICE as municipal-level agreements).

Historically, ICE has also over-counted the number of agreements by including the header row in their sum totals, and other typographical and data entry errors are common.