Typically, is the abdominal fascia cut during a c-section? If so, can it be repaired during a tummy tuck?

Thanks for your inquiry,  and you are correct the muscle and fascia can be repaired at the time of a tummy tuck, hope that helps,  best of luck.  

Hello and thank you for your question.  A tummy tuck can be designed to repair the fascia.  Scar tissue can also be removed during a tummy tuck.  If you are an appropriate candidate for a tummy tuck, this can be done through a low and short
incision, all completely below the bikini line. 
The belly button can be designed to look natural and have no scars on
the exterior.   Your muscles can also be
plicated resulting in a flat abdomen. 
Make sure you specifically look at before and after pictures of
real patients who have had this surgery performed by your surgeon and evaluate
their results.  The most important aspect is to find a surgeon you are
comfortable with. I recommend that you seek consultation with a qualified
board-certified plastic surgeon who can evaluate you in person.
Best wishes and good luck.
Richard G. Reish, M.D.
Harvard-trained plastic surgeon

It is difficult to say for sure without seeing a picture, but it sounds like the deformity you are describing is because of scarring underneath the skin. This results in tethering of the skin to the underlying fascia and a depressed (or indented) looking scar. This is very common after a c section.
During a full tummy tuck, the previous c-section scar can usually be removed as part of the skin excision, which generally corrects this deformity.