Managing concurrent serialized interrupt broadcast commands in a multi-node, symmetric multiprocessing computer including receiving, by a communications adapter in a compute node, a plurality of serialized interrupt broadcast commands; receiving, by the communications adapter, a plurality of interrupt tags for the plurality of serialized interrupt broadcast commands, each interrupt tag including an identification of an interrupt service order for a serialized interrupt broadcast command; assigning, by the communications adapter, to each serialized interrupt broadcast command its interrupt tag; and if an interrupt tag assigned to a serialized interrupt broadcast command has an interrupt service order that matches a value of a current operation tag that identifies the next serialized interrupt broadcast command to be exposed to the one or more processors, exposing, by the communications adapter, the serialized interrupt broadcast command to the one or more processors on the compute node to be serviced.