Abstract Consider a Lamperti–Kiu Markov additive process $(J, \xi)$ on $\{+, -\}\times\mathbb R\cup \{-\infty\}$ , where J is the modulating chain component. First we study finiteness of exponential functional and then consider its moments tail asymptotics under Cramér’s condition. In strong subexponential case determine tails some further assumptions.