Originally Posted by NewbieRunner

In that case you could have posted your question in the Miles & More forum but you will have received the same answer.

In MUC you will arrive on Level I and go two levels down to Level G through security and passport control. The minimum connecting time at MUC is currently 40 minutes, so you should have more than enough time.

In FRA your flight will arrive at an A gate and the flight to IAD is likely to depart from a Z gate which is one level up in the same part of the airport. You go through passport control but no security. Even some critics of FRA will say two hours should be enough for this connection. You may want to check the FRA connection guide in the M&M forum.

Make sure your luggage is checked through to IAD (if you are checking any).