Are there commissions associated with option exercise or assignment?

The answer depends upon the option type and its region of listing. There is no IBKR commission associated with an exercise or assignment of US stock and index security options and out-of-the-money non-US index options. A commission is charged for an exercise or assignment of an in-the-money non-US index option and for options on futures. Please refer to the Other Fees section of the IBKR website for details.