Sleep

When to Start Sleep Training - Methods and Safety

Editorially reviewed | Sources: AAP, NIH, AAP|Updated June 2026

The short answer

Sleep training refers to strategies that help babies learn to fall asleep independently. Most pediatric sleep experts and the AAP consider sleep training safe to begin around 4-6 months of age, when babies are developmentally capable of sleeping longer stretches and can self-soothe. Research consistently shows that sleep training methods - including "cry it out" approaches - do not cause long-term harm to babies' attachment, stress hormones, or emotional development. There are many methods ranging from gradual to direct, and the best approach is the one that works for your family.

Parents everywhere have the same worry. You are doing the right thing by looking into it.

By Age

What to expect by age

0-4 months

Formal sleep training is not recommended before 4 months. Newborn sleep is biologically driven and follows no trainable pattern. During this period, focus on establishing healthy sleep foundations: consistent sleep environment (dark, cool, white noise), age-appropriate wake windows, and beginning a simple bedtime routine. You can start gentle habits like putting your baby down drowsy but awake occasionally, with no expectation of success.

4-6 months

This is the earliest recommended window for sleep training. By 4 months, most babies have developed the neurological maturity to sleep in longer consolidated stretches. They have also developed the ability to self-soothe (sucking hands, turning head). Ensure your baby is not still in a 4-month sleep regression before starting. Methods range from Ferber (timed check-ins) to chair method (gradual parental withdrawal) to full extinction (placing baby down and not returning until morning).

6-12 months

This is the most common age for sleep training and often the easiest. Babies have the physical development to sleep 10-12 hours at night without feeding (though some may still need one feed). Separation anxiety can emerge around 8-9 months, which may temporarily complicate training. If you start during this window, most methods show significant improvement within 3-7 nights. Consistency is the most important factor regardless of method.

12-24 months

Sleep training a toddler is still possible but can be more challenging because toddlers are more aware, more mobile, and have stronger wills. They may climb out of the crib, call for you repeatedly, or have genuine fears. Toddler sleep training often involves more behavioral strategies - clear expectations, consistent responses, and lots of positive reinforcement. The "excuse me" drill and "silent return" are common toddler-specific approaches.

What Should You Do?

When to take action

Probably normal when...
  • Your baby protests for a short time at bedtime during sleep training but is consolable and the protests decrease over several nights
  • Your baby wakes once at night for a feed during the training process - one night feed is biologically appropriate until about 9-12 months
  • Sleep training takes 3-7 nights to show significant improvement - this timeline is typical
  • Your baby seems perfectly happy and attached to you during the day despite protesting at bedtime
Mention at your next visit when...
  • Your baby is still waking multiple times per night after 2 weeks of consistent sleep training with no improvement
  • You suspect your baby has a medical reason for poor sleep (reflux, ear infection, sleep apnea)
  • You are struggling with the emotional difficulty of sleep training and need support or guidance on choosing a method
  • Your baby is under 4 months and you are exhausted and need sleep strategies appropriate for young infants
Act now when...
  • Your baby has pauses in breathing, loud snoring, or gasping during sleep that may indicate sleep apnea
  • You are so exhausted from sleep deprivation that you are at risk of falling asleep with your baby in an unsafe location
  • Your baby is ill with fever, vomiting, or seems unwell - pause sleep training during illness and resume when they recover

Sources

Trust your instincts. If something feels wrong, reach out to your pediatrician.

Worrying about your baby means you care. That is a good thing.

Baby Sleep Associations

Sleep associations are the conditions your baby connects with falling asleep - rocking, feeding, a pacifier, or being held. They are completely normal and not "bad habits." If they are working for your family, there is no need to change. If frequent night waking from needing those conditions recreated is exhausting you, gentle gradual changes can help.

Baby Cries Every Time You Put Them Down to Sleep

Many babies cry when placed in the crib because they have learned to associate falling asleep with being held, rocked, nursed, or bounced. This is called a sleep association, and while it is not harmful, it means your baby needs that same condition to fall back asleep each time they wake during the night. Gradually teaching your baby to fall asleep in their sleep space - at whatever pace works for your family - is the foundation of independent sleep. This does not mean you are doing anything wrong; you are meeting a developmental need while gently building a new skill.

Baby Not Sleeping Through the Night

Waking during the night is biologically normal for babies and does not mean something is wrong. Most babies are not developmentally ready to sleep a full 8-12 hour stretch until at least 6 months of age, and many healthy babies continue to wake once or twice a night well into the first year.

How Long Should Baby Be Awake Between Naps?

The ideal awake time between naps (called a "wake window") increases as your baby grows. Newborns may only handle 45-90 minutes awake, while toddlers can manage 4-6 hours. Getting wake windows right is one of the most effective ways to improve nap quality, because both too-short and too-long wake times lead to poor sleep.

Is a Bath Before Bed Really Necessary?

A nightly bath is not medically necessary and some babies with sensitive skin do better with less frequent bathing. However, a warm bath can be a powerful sleep cue because the subsequent body temperature drop triggers melatonin production. If you include a bath, keep it calm and warm rather than stimulating.

How Long Should the Bedtime Routine Be?

An ideal bedtime routine for babies and toddlers is 20-30 minutes. Shorter routines may not give enough time to wind down, while routines longer than 45 minutes can become a stalling tactic. Consistency in the routine order matters more than exact length.