Read two manuals before touching the seat
The car seat manual tells you what the seat allows. The vehicle manual tells you what your back seat allows. NHTSA advises parents to read both before installation because lower anchor positions, seat belt locking methods, tether anchor locations, and center-seat rules vary by vehicle.
If you are still choosing a seat, start with how to choose a car seat, then use the car seat safety checklist before buying.
Most installations use either LATCH or the seat belt, not both. Some seats have special instructions, so the manual always wins.
The seven checks that matter
The back seat is the standard location. Confirm whether your vehicle permits the center position for your chosen method and whether the seat sits flat without tilting.
Use lower anchors if the child and seat are within the stated LATCH limits. Use the seat belt when required by the manual, when lower anchors are not available, or when the child exceeds the lower-anchor weight limit.
Rear-facing and forward-facing belt paths are different. Follow the color coding and label on the car seat shell, then remove slack from the belt path before locking the belt or tightening lower anchors.
After tightening, grip the seat at the belt path and move it side to side and front to back. It should not move more than one inch at that point. Movement at the top of a rear-facing seat is not checked the same way.
Rear-facing seats need the correct recline angle so the baby's airway stays open. Newborns often need the most reclined allowed setting. Older babies may use a more upright allowed setting if the manual permits it.
The top tether reduces forward movement in a crash. Locate the approved tether anchor in the vehicle manual and attach the tether when the seat is forward-facing with a harness.
Harness straps should be routed at or below the shoulders for rear-facing and at or above the shoulders for forward-facing, unless the manual gives model-specific instructions. The chest clip belongs at armpit level.
Have a CPST check it
A Child Passenger Safety Technician can inspect the installation and teach you how to repeat it. NHTSA maintains installation tips and an inspection-station locator; use those official resources before relying on confidence alone.
Helpful official resources: NHTSA car seat installation tips and NHTSA installation help and inspection locator.
Install the seat at least two weeks before the due date, then get it checked before the first ride home. Recheck after moving the seat to another vehicle.
Before you buy or reinstall
Use the full car seat checklist to verify certification, recall status, harness fit, installation confidence, and day-to-day use.
Open Car Seat Checklist →