Possibly a member of the Vigintiviri, his first attested position was as Tribunus laticlavius of the Legio IV Scythica, posted in Syria.
This was followed by an appointment as Legatus Augusti pro praetore (or imperial governor) of Arabia Petraea sometime between AD 200 and 207.
Sometime around this period, between 203 and 214, Marius Perpetuus was appointed suffect consul, the most likely dates being AD 203, 208 or 214.
Sometime between AD 204 and 211, Marius Perpetuus was the curator rerum publicarum Urbisalviensium (in Piceno) item Tusculanorum, and this was followed by his appointment as Legatus Augusti pro praetore in Moesia Superior, probably from AD 211 to around 214.
Then, possibly in 214, or 215/6, he was again Legatus Augusti pro praetore, this time of the province of Tres Daciae.