Makes sense to me. But then, I've been playing this "how to waste as few Club Miles as possible" game for quite some time now. Last year, using some creative travel planning I managed to qualify for Gold on a very short YYZ-ORD hop on AA, so I wasted almost nothing!

Basically, to answer the OP's question properly, we need to know if he is already DM trying to requalify, or if he is GO trying to become DM. The answer will be different depending on which case.

QRC3288 answered for both cases, correctly.

Elsewhere, someone mentioned that if you've already requalified, you can ask MPC to reset your year early. Is that really possible?