This is an irregular verb. It follows the conjugation pattern of the verb buscar.
PresentPresente
La profesora comunica las notas por correo.
The teacher communicates the grades by email.
PreteritePretérito indefinido
Ayer comuniqué la noticia a mi familia.
Yesterday I communicated the news to my family.
FutureFuturo
La empresa comunicará los resultados el lunes.
The company will announce the results on Monday.