Section 121 gains exclusion reported on what IRS forms if home was rental for 2 yrs??

[Jason V.]

It's my understanding that if there's a "partial exclusion", I'd use a Form 8949 with Code H...

And if it's "fully excluded" and there's no 1099-S issued (which I indeed received no 1099-S), then I'd simply not mention it at all.

But my biggest question is.... How do I determine if my being used as a rental for 2 out of past 5 years makes it fully or partially excluded?!?

Much thanks appreciated!!