。
I'm planning to move next month.
Literal
Next-month [on-に] move [schedule-予定] is.
[verb plain] + 予定です marks a scheduled plan — more objective and externally-anchored than the volitional ~つもり. 引っ越す ('move residence') is used directly as a verb here, unlike the noun 引っ越し form. The に on 来月 marks the time at which the move is planned.