I am trying to understand why the numbers of households in the universe in a 1-year supplemental file for a geographic unit also found in the acs 1 year data file, for what seems to be the exact same question, would be radically different. I am seeing this in estimates for unified school district geographies.

An example: I am comparing B28008-001E, from both the ACS 1 and 5, to K202801-001E from the ACS Supplement, all for 2019. The ACS supplemental estimate of total households is in many cases 1/4 to 1/2 of the ACS 1 and 5 total household numbers, which are usually pretty close, for any given unified school district found in all three datasets. The universe for all three tables, I believe, is households.

I think I must be missing something obvious....

Any help understanding what is going on would be greatly appreciated. Thanks!