While it appears you can print this one as many times as you want, however you can only use one coupon per transaction. Of course, it's not below me to go through the line several times to make several transactions. The coupon is good until May 22.
Now, there are some restrictions. You can't use it on "Buy one, get one" events; non-merchandise; concessions; federal or state regulated items; alcohol; tobacco; fuel; items behind the pharmacy counter; prescriptions; prior purchases; partial-paid special order items; Lands' End; Two Hearts Maternity; Sears merchandise rung on Sears registers within Kmart and some other legal mumbo jumbo. That said, I think there is plenty of the store that qualifies.
If you're a regular Kmart shopper, you may also want to consider singing up for Kmart's email savings club here, which promises to send you email deals several times a week, starting with two coupons for $5 off a $50 purchase.