Ready a spell, should there be a concentration check for all spells?

@luminapinaMage slayer/ready action hits while casting a spell. Should there be a concentration check for all spells, excl. maybe cantrips? readied action takes place after trigger, so first spell then attack. No check needed.

— Mike Mearls (@mikemearls) October 8, 2014

@luminapinaOkay, thank you. So Counterspell is the only way to interrupt the casting of spells with one action or shorter casting times? Correct, at least with what's available in the PHB.

— Mike Mearls (@mikemearls) October 8, 2014