We investigate the number of parts modulo~$m$ of $m$-ary partitions of a positive integer~$n$. We prove that the number of parts is equidistributed modulo~$m$ on a special subset of $m$-ary partitions. As consequences, we explain when the number of parts is equidistributed modulo~$m$ on the entire set of partitions, and we provide an alternate proof of a recent result of Andrews, Fraenkel and Sellers regarding the number of $m$-ary partitions modulo~$m$.
"The distribution of the number of parts of $m$-ary partitions modulo $m$." Rocky Mountain J. Math. 47 (6) 1825 - 1838, 2017. https://doi.org/10.1216/RMJ-2017-47-6-1825