I posted about TAM and US Airways exiting Star Alliance back in March, and it is now your last opportunity to book a reward on them using your KrisFlyer Miles.
Officially TAM and US Airways exited Star Alliance and joined Oneworld on the 31st of March. However they left it open until the 31st July for booking rewards and earning Miles. For TAM and US Airways you can only book rewards and fly until the 31st July, but with US Airways you can travel until the 27th July 2015 (360 Days). All reward bookings use the usual Star Alliance redemption charts which can be found here.
Unfortunately, if you were looking for a redemption of a flight upgrade this was only available until the 31st of March.
In addition to this if you do forget to input your KrisFlyer number, you’ll be able to retroactively claim until the 31st January 2015 for US Airways. There is no mention for retroactive claims for TAM Airlines.
You can find the official announcement from Singapore Airlines and KrisFlyer here.