Usually, when switching from Methadone Maintenance to Sub Maintenance, they make you wait longer before they start you on Subs (i.e., more than 24 hours, especially since you have been on it for a year) and / or even switch you from methadone to a shorter-acting full agonist for a few days, like an equivalent dose of oxy or morphine, THEN when the methadone is out of your system and you go into w/d