Hello, need some clarification :

I am Frequent Flyer with Miles and More and Gold Status with AA.

Should have flown with Lufthansa to Miami but the flight was canceled and rerouted with British Airways.

Now I would like to redeem my 'retroactive miles', but :

1 Can I do it with Miles and More even if BA is not in Star Alliance ?

or

2 Put them in AA (tried the ticket number on the website but it is not recognized)

Thanks forthe help !!!

You're not looking to "redeem" retroactive miles; you're looking to claim them.

To claim AA miles for BA flights, you must go through AA. If AA does not recognize the ticket number, be prepared to submit your BA boarding passes. (Did LH or BA re-issue your ticket -- with a different ticket number -- after you were rebooked on BA?) You might have to call AAdvantage Customer Service and explain your situation to get credited with AAdvantage miles.

Things would have been easier for you if you had provided BA with your AAdvantage number before flying your BA flights.

Depending on LH's policy on giving "original routing credit," you might be able to claim Miles and More miles for your originally-scheduled LH flights, in addition to claiming AAdvantage miles for your BA flights.

Good luck.

1) You will not be able to apply the miles flown on BA to Miles and More, but it should be possible for you to obtain "original routing credit" (use these exact words) on Miles and More" for the LH flight you were originally scheduled to take to Miami.

2) You should also be able to receive credit on AA for the flights you actually took on BA, upon request.

I see no reason why you could not do both of these, under the circumstances. Be sure to retain all tickets and boarding passes until credit is received, as you may need to document your travels.