[3] He won Boys U12 Doubles with Sebastian Oña at the International Racquetball Federation (IRF) World Junior Championships in Cochabamba, Bolivia.

[5] In 2013, Moscoso won Boys U18 Singles at the World Junior Championships in his hometown of Sucre, Bolivia, where he defeated Mexican Rodrigo Garay in the final, 10–15, 15–9, 11–10.

[6] He was runner up in Boys U18 Doubles with Sebastian Oña that year, losing in the final to Rodrigo Garay and Javier Mar of Mexico, 15–8, 15–14.

[11] Moscoso played Men's Doubles with Mario Mercado, and they lost to Colombians Sebastian Franco and Alejandro Herrera, 15–11, 15–2, in the semi-finals.

At the 2015 Pan American Championships, Moscoso reached the semi-finals in Men's Singles, but lost to Jose Diaz of the US, 10–15, 15–13, 11–6, resulting in a bronze medal.

In singles, Moscoso defeated Costa Rican Felipe Camacho in the Round of 16, 15–11, 15-9 and team-mate Carlos Keller, 15–3, 15–5, but lost in the semi-finals to Álvaro Beltrán, 15–9, 15–3.

In doubles, he and Roland Keller beat Sebastian Franco and Alejandro Herrera of Colombia in the quarterfinals, 8–15, 15–9, 11–6, Vincent Gagnon and Tim Landeryou of Canada, 15–11, 15–9, but lost the final to the USA's Jansen Allen and Jose Rojas, 15–8, 15–5.

He defeated Fernando Rios of Ecuador, 11–15, 15–0, 11–1, in the quarterfinals, so in the semi-finals he faced Rocky Carson of the US in what was a rematch of the 2014 World Championship Men's Singles final.

[15] Moscoso played both Men's Singles and Doubles at the 2017 Pan American Racquetball Championships in San José, Costa Rica.

[16] In Men's Doubles, he and Roland Keller defeated Felipe Camacho and Teobaldo Fumero of Costa Rica, 15–2, 15–7, in the quarterfinals, but lost to the USA team of Jake Bredenbeck and David Horn, 15–12, 15–7, in the semi-finals, resulting in a bronze medal.

[19] At the 2018 Pan American Racquetball Championships in Temuco, Chile, Moscoso played Men's Doubles with Roland Keller, and they reached the final by beating Costa Ricans Felipe Camacho and Teobaldo Fumero, 15–2, 15–5, in the quarterfinals, and Jose Daniel Ugalde and Juan Francisco Cueva of Ecuador, 15–8, 15–1, in the semi-finals.

[22] But at the Bolivian Open in Cochabamba, Moscoso defeated David Horn in the Round of 16, 15–5, 15–6, Alejandro Landa, 15–9, 11–15, 11–0, in the quarterfinals, Álvaro Beltrán in the semi-finals, 15–10, 15–6, to play Rocky Carson in the final.

In singles, Moscoso defeated the USA's Charlie Pratt in the quarterfinals, but lost to Mexican Rodrigo Montoya, 15–14, 15–10, in the semi-finals, resulting in a bronze medal.

In doubles, Moscoso and Keller beat Coata Ricans Andres Acuña and Felipe Camacho, 13–15, 15–12, 11–7, in the semi-finals, but lost the final to Mexicans Álvaro Beltrán and Montoya, 15–10, 15–1.

He got to the final by defeating Rocky Carson in the Round of 16, 15–13, 15–5, Sebastian Fernandez in the quarterfinals, 15–4, 15–4, and Daniel de la Rosa in the semi-finals, 15–11, 15–11.

[33] He was also a bronze medalist in Mixed doubles with Angélica Barrios, as they lost in the semi-finals to Argentina's Diego Garcia and Maria Jose Vargas, 9-11, 11-8, 11-8, 10-12, 11-9.