Miles & More upgrade vouchers will now expire after 24 months from the date they were credited to your account. Lufthansa is lessening the blow a bit by implementing transitional expirations for eVouchers you already have. Your eVouchers credited by June 30, 2010 will remain valid for a further 36 months, until July 1, 2013, and eVouchers credited between July 1, 2010 and March 30, 2011 will also expire on July 1, 2013. But for all eVouchers credited from April 1, 2011 onwards, the validity period will be for 24 months only.
Also, as of last month, retroactive mileage is available for six months after a mileage earning transaction, down from 12 months.