In the rush to get through airport security checkpoints, it is not uncommon for distracted travelers to leave laptops, cellphones, jewelry and other valuable items in the plastic bins needed to scan their belongings.
As it happens, they also leave behind lots of accumulated cash.
For its fiscal year 2016, the Transportation Security Administration reported that passengers left behind more than $867, 812.39 in coins and currency in the plastic bowls and bins at various U.S. airport checkpoints. That's about $102,000 more than the amount left behind in 2015, and the more than $484,000 left behind in 2008.
Over the years, the amount of change left behind by travelers at airports has been steadily climbing—jumping from about $489,000 in 2011 to almost $675,000 in 2014, and hitting $766,000 in 2015.
"There is no real way for TSA to know why this happens," spokeswoman Lisa Farbstein told CNBC. "It makes sense to point to an increase in the number of travelers as one likely reason, but other than that, we have no theories."
Last year, passengers at New York's John F. Kennedy International Airport were the most forgetful (or generous, perhaps): Travelers there left behind $70,615 in unintentional 'tips' for TSA.
Also on the top ten list for fiscal year 2016: Los Angeles International Airport, where travelers left behind almost $45,000; and Dallas/Fort Worth International Airport, where more than $42,000 in cash and currency was abandoned.