is a "mandevlla" plant one that comes back each year?

It is tropical, so where I live in Massachusetts it will not come back unless you bring it in the house for the winter.

I would guess that in the United States anything North of the Carolina's is too cold for that plant to winter over.

It is a tropical plant that does not return after a hard freeze. North of Lake Pontchartrain in zone 8b, where freezes are minimal, the mandevilla is not hardy. But it is worth it to buy another one each spring. Or to mulch the vine well at the roots and cover it during any freeze.

It's a tender tropical perennial vine that will not survive a freeze here in the U.S. unless its in a container and you can bring it inside for the winter, or if not then give it some heat and protection from frost in its planting location.