The disclosure generally relates to an adjustable foundation or bed, in particular having a dual-tilt adjustable foundation. Upper and lower segments of the adjustable foundation subframe are rotatable relative to each other, thus allowing the upper portion of the subframe to tilt and assume an inclined, flat/horizontal, or declined position relative to the lower portion of the subframe. An articulating mattress support surface above the subframe can move independently from the tilting subframe.