If your baby was sleeping more predictably and suddenly started resisting naps, waking overnight, or fighting bedtime around 12 months, you may be seeing the start of a 12 month sleep regression. Learn what timing is typical, what signs to look for, and get personalized guidance for what to do next.
Answer a few questions about when the sleep disruption started, what changes you’re noticing, and your child’s age to get a clearer sense of whether this fits the usual 12 month sleep regression timing.
The 12 month sleep regression start often shows up as a noticeable shift in sleep habits around your child’s first birthday. A baby who had been settling well may begin waking more at night, resisting naps, taking shorter naps, or becoming harder to put down at bedtime. For some families, the change feels sudden. For others, it builds over a couple of weeks. This stage is often linked to rapid development, growing awareness, separation concerns, and changes in nap needs, which can all affect sleep timing and quality.
Your 12 month old may suddenly protest bedtime, take longer to fall asleep, or seem more alert right when it is time to settle.
A child who had been sleeping more consistently may begin waking overnight again, sometimes needing more help to resettle.
Short naps, skipped naps, or fighting one or both naps can be an early sign of toddler sleep regression at 12 months.
Around this age, many children are learning new motor, language, and cognitive skills. That extra brain and body activity can temporarily disrupt sleep.
Your child may become more aware of your presence and absence, which can make bedtime and overnight wake-ups feel more emotional.
The 12 month sleep regression age often overlaps with changing sleep needs, including nap transitions, overtiredness, or wake windows that no longer fit.
When does 12 month sleep regression start? Despite the name, it does not begin on the exact first birthday for every child. The 12 month sleep regression timing can begin a little before 12 months or shortly after, depending on development and schedule changes. Some families notice it around 11 months, while others see it closer to 12 or 13 months. Looking at your child’s age, recent milestones, and the pattern of sleep changes can help you tell whether this is likely a regression or something else affecting sleep.
For many children, this phase is short-lived and improves as development settles and routines become more consistent again.
How long the 12 month sleep regression lasts depends on factors like nap timing, sleep habits, temperament, and whether multiple changes are happening at once.
If sleep disruption continues beyond a brief developmental phase, it can help to look more closely at schedule fit, bedtime routines, and other possible causes.
The 12 month sleep regression start is often noticed sometime around the first birthday, but it can begin a bit earlier or later. Many parents see changes between 11 and 13 months rather than on one exact date.
Common 12 month sleep regression signs include bedtime resistance, more night waking, shorter naps, nap refusal, early rising, and a child seeming more unsettled or harder to resettle than usual.
It can start even after a good stretch of sleep because this age often brings major developmental changes, stronger separation awareness, and shifting nap needs. Those changes can temporarily disrupt previously steady sleep.
There is no single timeline, but for many families it is a temporary phase. If the sleep disruption continues or becomes more intense, it may help to look at schedule changes, sleep habits, or other factors beyond a regression.
If you are wondering whether this is really the start of a 12 month sleep regression, answer a few questions for an assessment tailored to your child’s age, sleep pattern, and current signs.
Answer a Few QuestionsExplore more assessments in this topic group.
See related assessments across this category.
Find more parenting assessments by category and topic.
When Sleep Regressions Start
When Sleep Regressions Start
When Sleep Regressions Start
When Sleep Regressions Start