There are no direct buses from Cochabamba to Cusco. The most efficient way to do this trip is to travel first from Cochabamba to La Paz, and then from La Paz to Cusco.
The bus from Cochabamba to La Paz takes around 8 hours, covering a distance of 378 km and crossing valleys and the Bolivian altiplano. Buses depart from the main bus terminal in Cochabamba located on Avenida Ayacucho. Before departure you will have to pay a small fee (around us$0.50) for the maintenance tax of the bus terminal. In La Paz, buses arrive on Avenida Peru, near the center of the city. Departures to Cusco are from that same terminal.
La Paz to Cusco by bus takes between 12 and 15 hours depending on the bus company and on how long it takes to clear migration, and the distance between the two cities is 655 km. Buses cross the border either in Desaguadero or in Pisiga-Colchane (near Copacabana), depending on the bus company and route you choose. In Cusco, the buses arrive at the main bus terminal. With Tickets Bolivia you can compare prices and book tickets online to travel between Cochabamba and Cusco. You can pay by credit card, debit card or via payment platforms such as PayPal and Stripe.