Yes, the UPPAbaby Mesa infant car seat includes one base with purchase.
The Mesa infant car seat can also be installed without its base for use in other vehicles or while traveling, and you can purchase an additional base for other vehicles that you'll be using regularly to transport baby.
You can purchase an additional Mesa car seat base separately for $129.99.
How to install the UPPAbaby Mesa without Base
To install the Mesa infant car seat without a base, use the included seat belt paths to secure the Mesa car seat using the vehicle seat belt according to the manufacturer instructions for seat belt installation as shown in this demonstration:
Shop the Mesa infant car seat below!