Question on Idaho Property Tax

[Jon Fults]

Hi all - this is my first post on BP. I am just getting into this space and own a couple of properties currently in Utah. I am currently looking at a multi-family property in SE Idaho (would be my first in the state) and after a bit of research I have a few lingering questions about how Idaho state property taxes work. I understand the basic gist which seems to be that a property is assessed every 5 years at the current market value and there is a significant homestead exemption for owner-occupied homes.

However, what I am finding hard to get my head around is that the actual taxes assessed seem (at least at the few properties I've looked at) seem to fluctuate more than I'd expect. And what's more is the basis on most of the properties I've seen are substantially under what market is. I know Idaho has had some heavy appreciation over the past few years, so perhaps the state and counties just haven't had enough time to catch up. In any case, my question is what triggers a property reassessment? Is an assessment triggered at the time of sale or is it truly down on a "best efforts" calendar basis. And how long is it reasonable to expect that I'd pay a tax on the basis that's significantly lower than market. It seems to me like the "safe" underwriting is to assume that taxes increase to market (aka purchase price) on day 1 and anything below that is gravy.  

Also - probably a dumb question - are the Idaho property tax assessments public domain? After a handful of google searches I wasn't able to find a location to find previous years assessments. The only place I have been able to find previous years assessments is on the broker-provided property tear sheets. 

Thanks in advance for any insights and responses.