I sent an email to their customer care the other day and this was the response I got. Thought y'all might be able to use it as well.

Dear __________,

I would like to provide you with an answer to your question regarding
the number of Extra Bucks that may be used per purchase.

Our registers are set to allow 1 CVS coupon and 1 manufacturer coupon
per item. However, the staff should be allowing customers to use Extra
Bucks in combination with other CVS coupons since these are coupons you
have "earned." In addition, similarly they should be allowing the use
of "offer at the register" coupons, which would be an open offer of $3
off of $15 or a certain dollar amount off of a specific item. Since our
registers are programmed to only accept 2 coupons (1 CVS, 1
manufacturer) per item if the number of coupons exceed the items
purchased a member of management will need to assist the cashier in
processing the coupons. I apologize in advance for any inconvenience
this may cause.


If you have any other questions please do not hesitate to contact us
either by e-mail or by calling (800) 746-7287. Thank you for taking the
time to contact us. I hope you have a nice day.
Sincerely,
Donna Roy
CVS ExtraCare

So, does this mean that they should be allowing us to stack coupons? (such as $4/$20 in combination with $3/$15, $2/$10 so on and so forth?)

That's a good question and the answer is not very clear. Maybe I'll have to write back and ask for clarification. ;o)

I asked specifically about Extra Bucks and $/$$ coupons and this was her reply (makes things about as clear as mud ;o),

Dear __________,

ALL Earned Extra Bucks coupons associated with an ExtraCare card may now be redeemed in a single transaction. The retail price must be greater than the combined total of all coupons. Please keep in mind there is no cash value back for any unused portion of the coupon. Please
remember that the use of manufacturer coupons remains limited to one per item in any transaction.


If you have any other questions please do not hesitate to contact us
either by e-mail or by calling (800) 746-7287. Thank you for taking the
time to contact us. I hope you have a nice day.
Sincerely,
Donna Roy
CVS ExtraCare

I think they try to avoid answering that question about stacking totally. If eveyone knew we could stack, then they would go out of business....so only the select, smart ones know...like us. As long and the amount of coupons doesn't exceed the number of items....1 cvs coup + 1 manufact. per item....makes sense, but cashiers don't know...managers don't even know.