Is there a time frame where B and C shares do not have back end fees? And do you have to keep them for a specific time frame?
Generally, B shares will be penalty free after 7 years and convert into A shares at that time. C Shares will be Contingent Deferred Sales Charge (CDSC) free after a 12 month holding period. You should be able to exchange funds within the same fund family, but if you choose to liquidate, you may incur a fee.
Generally, after a certain time period Class B loaded shares, loads or commissions decline in percent and go away completely. Class B are named such as there is no front end commission on the purchase of shares, but most likely will have a back end or surrender commission if liquidated (and possibly a transaction charge from the platform provider) during the afore mentioned time period. Depending on the situation frequently B class shares automatically convert to lower expensed A or other like kind shares after the surrender/commission time period expires.
Class C or level loaded shares, generally have an ongoing or level loaded share class. As such, there, in most cases, will be no decline in fee as the fee is being assessed on a regular basis. In most cases there will be no share class commission (may be a transaction charge) to change, move or redirect your funds from a Class C share fund.