Safe Crib Sleep Setup: Every Element That Matters and Why

For every nap and night sleep, place baby on their back in their own empty sleep space: a firm, flat, level crib mattress with a tightly fitted sheet only. Do not add soft bedding, pillows, bumpers, toys, positioners, or inclined inserts.

The simplicity is deliberate. A safe sleep setup is not a more padded, decorated, or “supported” crib. It is a properly assembled sleep space with a clear surface and no loose or soft additions.

Start Every Sleep on Baby’s Back

Place infants on their backs for every sleep, including naps, until age 1. This is the starting position even if baby has begun rolling.

• Place baby down: On their back, on the clear mattress.
• If baby rolls independently during sleep: If baby can roll independently in both directions, you do not need to turn them back; keep the sleep space empty and safe. If baby can roll only one way, you may reposition them onto their back.

Rolling does not make stomach placement an acceptable way to start sleep. It does mean the crib setup matters even more: there should be nothing in the sleep area that could press against baby’s face, restrict movement, or create an entrapment hazard.

For at least the first 6 months, use room-sharing setup for the first months keeps baby’s separate sleep surface in the caregiver’s room—not in the same bed. The American Academy of Pediatrics’ parent guide to safe sleep describes back placement, a firm flat surface, and a separate approved sleep space as core practices.

Build the Sleep Surface: Firm, Flat, Fitted

A crib mattress is supposed to feel firmer than an adult mattress. Infant sleep safety is not based on the cushioned feel an adult may expect; it depends on a surface that is firm, flat, level, and does not indent under baby.

Use this as your setup check:

A fitted sheet is bedding, not an invitation to layer the mattress. Do not add a pillow-like pad, foam insert, topper, or another mattress to make the surface feel softer or more comfortable.

Use a crib, bassinet, portable crib, or play yard only when the specific product meets applicable Consumer Product Safety Commission standards. A product category alone is not a safety guarantee: confirm the instructions and intended sleep use for the exact product you have.

Keep the Crib Empty

For sleep, the crib should contain baby and the fitted sheet—nothing else.

Remove:

• Pillows
• Loose blankets, quilts, and comforters
• Stuffed animals, lovies, and toys
• Bumper pads, including mesh bumpers
• Mattress toppers and extra mattress pads
• Nests, pods, and in-bed sleepers
• Wedges
• Inclined sleep inserts or inclined sleepers
• Hammocks, baby boxes, tents, or other products not verified for infant sleep
• Weighted blankets and weighted sleepers

These items may look cozy, help a nursery look finished, or be marketed around comfort, rolling, reflux, or “breathability.” None of those claims changes the basic setup rule: baby needs a firm, flat, clear sleep surface.

Infant sleep surfaces should be firm, flat, and level—not inclined or elevated. Do not raise one end of the mattress or add a wedge, including for reflux. Likewise, a product called a nest, pod, travel bassinet, or compact bassinet should not be assumed safe for sleep solely because of its name. Verify that the individual product complies with applicable federal standards and follow its original instructions.

A monitor does not make an unsafe setup safe, and consumer heart-rate, breathing, oxygen, or motion monitors should not be used as a strategy to prevent SIDS. Use a medical monitor only when prescribed for an infant’s specific condition. Place any monitor and its cords at least 3 feet (0.9 m) from the crib and keep all cords out of reach.

Dress Baby for Sleep Instead of Adding a Blanket

When a crib is bare, warmth should come from baby’s clothing rather than loose bedding.

A practical starting point is to dress baby in only one layer more than you are wearing. Adjust based on baby and the room, rather than adding a blanket to the crib.

Watch for possible overheating signs such as:

• Sweating
• A hot chest
• Flushed skin

Do not use indoor sleep hats after leaving the hospital. Hats can add warmth when baby cannot easily regulate it by removing a layer.

If you use sleep clothing, choose an option that fits properly, matches baby’s developmental stage, and is used according to its instructions. Do not use weighted sleepwear or weighted blankets for infant sleep.

Stop swaddling before rolling attempts

Stop swaddling as soon as baby starts trying to roll, which may occur around 3 to 4 months or earlier. Do not wait for a particular age. Always place a swaddled infant on their back, and never use a weighted swaddle.

Swaddling does not reduce the risk of SIDS. Once it is time to stop, do not replace it with a wedge or weighted item. Return to the same foundation: back placement, fitted sheet, and an otherwise empty crib.

Recheck the Setup as Baby Develops

A crib setup is not a one-time task. It needs another look as baby becomes more mobile and begins to roll, sit, pull to stand, or try to climb.

Before using a crib or other sleep product

Check that:

• The product is intended for infant sleep and meets applicable safety standards.
• You are using the mattress intended for that product, without an added mattress.
• The mattress fits tightly.
• The fitted sheet is secure.
• No soft, loose, padded, or inclined items have been added.
• You have the original product instructions and are following them.

This is especially important with a hand-me-down or older crib. In the United States, use a crib manufactured on or after June 28, 2011, that meets current CPSC standards; do not use a drop-side crib or any crib with broken, missing, loose, or modified parts. Locate the manufacturer’s instructions for the exact model, confirm that all original hardware is present, and check the CPSC recall database before use.

When baby’s abilities change

There is no universal mattress-height setting or crib-exit age that fits every product. The correct timing depends on the crib’s instructions and its stated limits.

Lower the mattress before baby can sit independently and move it to the lowest position before baby can stand. Stop using the crib at the earliest of these points: the child begins climbing out, reaches 35 inches (89 cm) in height, or reaches an earlier manufacturer limit. Always follow the instructions for the exact crib.

If your baby has a medical circumstance that affects sleep positioning or equipment, ask your pediatric clinician for individualized guidance rather than adding an unapproved support to the crib.

Reset the Crib Tonight

Before the next sleep, check:

• Baby will be placed on their back.
• The mattress is firm, flat, level, and tightly fitted.
• The fitted sheet is the only bedding.
• The crib is empty: no blankets, pillows, toys, bumpers, toppers, nests, or wedges.
• Baby is dressed for warmth without a loose blanket or indoor hat.
• Swaddling has stopped before any attempt to roll.
• The product instructions and recall status have been checked.

Safe crib setup is intentionally simple, but it is only one part of a complete infant safe-sleep plan. Verify your specific sleep product’s instructions and recalls, speak with your pediatric clinician about individual medical needs, and follow current AAP guidance on other risk-reduction practices as baby grows.