Yes the Saatva Youth mattress can be used with bunk or loft beds, as long as the upper edge of the guardrail is at least five inches above the mattress for maximum safety. Because the Saatva Youth mattress is made with multilayer support, it is thicker than standard bunk bed mattresses, so please check with the manufacturer of your bunk bed.
The Saatva Youth mattress is 10'' tall.