An adjustable bed system includes first and second frames; a back lifting assembly having a back lifting bracket pivotally connected to the first frame and a back lifting actuator pivotally connected between the back lifting bracket and the first frame for operably driving the back lifting bracket to pivotally move in an upward or downward rotating direction relative to the first frame; a leg lifting assembly having a leg lifting bracket pivotally connected to the second frame structure and a leg lifting actuator pivotally connected between the leg lifting bracket and the second frame for operably driving the leg lifting bracket to pivotally move in an upward or downward rotating direction relative to the second frame; and a foldable connection mechanism connecting the first and second frames such that the first and second frames are pivotally foldable relative to one another at the connection mechanism.