1 . SOCIAL SECURITY FOR MIGRANT WORKERS - INVALIDITY INSURANCE - ACQUISITION OF THE RIGHT TO BENEFITS - CONDITIONS - TAKING INTO ACCOUNT OF THE PERIOD OF RESIDENCE IN A MEMBER STATE - MEMBER STATES EMPOWERED SO TO ACT ( REGULATION NO 1408/71 OF THE COUNCIL , ART . 48 ( 1 ) 2 . SOCIAL SECURITY FOR MIGRANT WORKERS - INVALIDITY INSURANCE - ACQUISITION OF THE RIGHT TO BENEFITS - CONDITIONS - COMPLETION OF THE MINIMUM QUALIFYING PERIOD SPECIFIED BY NATIONAL LAW - WHETHER THE RIGHT TO BENEFIT IS DEPENDENT ON THE WORKER ' S BEING INSURED AT THE TIME AT WHICH THE RISK MATERIALIZES - NOT DEPENDENT THEREON ( REGULATION NO 1408/71 OF THE COUNCIL , ART . 48 ( 1 ))