It can be multi-10K or just medical treatment bill that someone has to pay.

If it has bacteria in it then a chlorine treatment can fix that.

I think MA gets a bad rap as “tenant friendly”—most of the refs are simply about fair treatment, but in any case NH has a more “landlord friendly” reputation.

The asset is a Residential home that is leased (absolute Net) to a medical treatment facility. 

@Jill Widmer unlike your prior long-term rental the short-term rental has access to more favorable tax treatment.

Members of addiction treatment, clergy or social services?

So, first thing is first, you've addressed the pest issue, now it's time to hire a professional, serve notices to the tenants and (at least in NC) they cannot refuse treatment, they will be responsible for the bill.

If you've done this, in your experience was this an effective treatment, to at least buy a few years? 

Point being tax wise - the portfolio treatment of you lending and passive treatment on the syndication might not be all that bad.

This tax legislation extends or reverts to pre-2023 tax treatments of very favorable tax legislation that apply to real estate investors.