I would recommend at 4-6 weeks. At this age, your baby is getting up less and less in the middle of the night, and the sooner the transition happens the better. We did not feel comfortable moving our babies out of our room until this age. I am so glad we made the transition when we did, however, because they both got much better sleep as a result. We were able to start better routines, and they quickly learned that being in the crib meant it was time to sleep. Babies are noisy sleepers. When in our room in the bassinet, our babies kept everyone awake. We also responded to our baby too quickly at times. We really had to learn to ignore some noises, because babies can make noises while asleep and not be needing us.