You can apply to withdraw a portion of your CPF savings anytime from 55 whenever you have immediate needs for cash. There is no limit to the number of withdrawals you can make. Find out how much you can withdraw.
If you do not have an immediate need, you can leave your savings in your CPF accounts as rainy day funds while enjoying interest rates of up to 6% p.a., and withdraw them only when you need to. With PayNow, you can generally receive your withdrawn monies almost instantaneously.