Flying With a Baby on Alaska Airlines

The diaper bag rule, because it changes what you pack

Alaska’s lap infant page says it plainly: when traveling with a lap infant, a diaper bag will count toward the standard carry-on limit of the ticketed adult passenger, and lap infants are not entitled to their own carry-on allowance.

That is a meaningfully different position from the other carriers on this site. JetBlue publishes that you can bring one diaper bag, one stroller and one car seat for a lap infant — the diaper bag is extra. Alaska’s is not extra. It is the bag you were already allowed, now full of diapers.

The practical consequence is a packing decision, not a policy complaint. Either the diaper bag has to be a real carry-on that also holds your things, or everything adult-sized goes in a checked bag. A bag with a laptop sleeve and nearly a thousand cubic inches is doing a different job here than it does on an airline that gives the baby its own allowance. Our does a diaper bag count as a carry-on page covers how the major carriers differ, and best small diaper bags for travel ranks the bags that fit under a seat.

Alaska’s published infant rules at a glance

Where you are allowed to sit, which depends on the flight number

This is the most unusual thing Alaska publishes, and it is worth reading before you choose seats. Because of where the extra oxygen masks are fitted, the number of lap infants allowed in a row varies by the aircraft operating the flight — and Alaska expresses that by flight number range:

• Alaska flights 1-99, 200-799, 1300-1999: one lap infant per row, including both sides of the aisle.
• Alaska flights 100-199: one lap infant per section of the aircraft within a row.
• Flights operated by Hawaiian Airlines, 800-1299: one lap infant per section of the aircraft within a row.
• Flights operated by Horizon Air, 2000-2999: one lap infant on each side of rows 6-21.
• Flights operated by SkyWest, 3300-3499: one lap infant per row, on the right side of the aircraft only.

And on every Alaska and Hawaiian flight, lap infants are not permitted in the emergency exit rows.

Two families traveling together with a baby each cannot assume they will sit in the same row. If that matters to you — and on a regional Horizon or SkyWest flight it often will — sort the seats at booking rather than at the gate.

Car seats and strollers: free, and free at the gate

Alaska publishes that it will transport your child’s car seat and stroller free of charge as checked baggage, and that you can check them with your other bags or wait until you reach the gate area. Stroller-wagons designed to carry children are included if they collapse to under 90 linear inches and 35 pounds; anything larger, anything not designed to carry children, and a wagon carried in addition to a stroller falls under standard bag fees.

Gate-checking is the better plan with a baby, because it means you keep the stroller through the terminal and get it back at the aircraft door. The thing worth buying is a bag to put it in: the hold is hard on a stroller that goes back under a sleeping child an hour later. Our gate-checking a stroller page walks through the process, and best car seat travel bags covers the car-seat half.

The second birthday, and what to do about the seat

Alaska publishes that as of their second birthday children are no longer infants, and that the FAA requires every child who has reached their second birthday to occupy their own seat and travel on their own ticket. Once you are buying that seat, you have a choice about what goes in it.

The FAA’s own guidance is that the safest place for a child under 40 lb on an aircraft is an approved child restraint system, not an adult’s lap (faa.gov, read 2026-09-27). A car seat does that job and is also your car seat at the destination. A CARES harness does the aircraft half at 11 oz and does nothing in a rental car. Which one is right depends entirely on whether somebody is meeting you with a seat at the other end — our CARES harness vs car seat page runs the comparison, and car seat on a plane covers installing one in an aircraft seat.

What to do before you book

1. Decide the bag first. On Alaska the diaper bag is your carry-on. Pick one that works as both, or accept that your own things are going in the hold.
2. Check the flight number against the row rules if you are traveling with another family who also has a baby, or on a Horizon or SkyWest regional flight.
3. Take the free stroller and car seat check, and buy a bag for each. It costs almost nothing and the alternative is a wet stroller.
4. Bring paper proof of age. Alaska reserves the right to ask.
5. If the second birthday falls mid-trip, book the return as a seated passenger.

For how Alaska compares with the other carriers we have read, start at do babies need a ticket to fly, and for the airline whose infant rules sit at the opposite end of the spectrum, see flying with a baby on JetBlue.

The diaper-bag rule above has an exact opposite, and it is worth seeing the two side by side: Frontier publishes that an adult with a lap infant may bring a second personal item for the diaper bag at no charge, where Alaska counts the same bag against your own carry-on allowance. The published version is at flying with a baby on Frontier, which is also the only airline on this site that publishes minimum seat widths for a car seat.