The US is not currently a net importer.

As noted elsewhere, the coal currently imported is relatively small, and fills a particular niche. The imports are also related to particular transportation costs: it can be cheaper to import australian coal by boat at a particular port than to move it from Wyoming or West Virginia.

Well, that's a reminder to be sceptical of "facts". I've read elsewhere that we've become net importers of coal. I checked EIA for YTD data:

Imports: 27.3 million short tons
Exports: 36.8 million short tons.

I was skeptical also hence the question marks.

I was actually surprised to see any imports.

There was an ad on Australian TV where a shopper wants a plastic bag and the sales assistant asks 'how do you expect the environment to deal with that bag?'. Seems with coal the message is more like 'enjoy'.