Baby is ready to be carried in the Baby Mode (facing in) when they are taller than 23 in/58.4 cm - typically around 2 months. Because the waistbelt is secured with the panel hanging down like an apron, the Baby Mode - Facing In position allows for a longer back panel and wider supported seat for baby.
Babies shorter than 23 in/58.4 cm should be carried in the Newborn Mode – Facing In position, where the waistbelt is flipped inward twice to make the back panel shorter and seat width narrower.