if your child is climbing out of the crib, then it's probably time. my daughter climbed out of her crib at 6 months. she threw a leg over the side, pulled herself up and out, and then shimmied down the side. i thought i was going to have a heart attack. we put her in a playpen to sleep, and by 10 months, she figured out how to climb in and out. she's 21months now, and still sleeps in the playpen, because she knows that she has to stay in there until mommy comes to get her. we also have a baby gate in front of her door, so if the mood strikes her, she will still be in her room, safe. when she turns 2, we will put her on a mattress on the floor. she sleeps on this mountain-high pile of blankets, stuffed animals, and pillows, so i think she will be fine with the mattress, and a bed rail. that's the cheap way for us to go, because we have limited space in her room, and limited cash as well. hope this helps.