What is a tummy tuck incision depth?

Good question.  As a surgeon you need to go to the virtually the same depth when performing a skin only or full abdominoplasty.  This level is the layer right above the muscle called the anterior abdominal fascia. 

The depth is as deep as it takes to get down to the muscle and this varies from one individual to another

The tummy tuck incisions are all performed above the fascial layer of the abdominal muscles.  The muscles are brought together to tighten them.

Regardless of whether the muscle is plicated or not, the skin and underlying fat must be completely removed to obtain a flat defined contour.    Therefore, the incision is carried down through skin and fat to the fascia (protective layer over muscle).    It is quite common to plicate the muscle during any tummy tuck procedure to help restore the hour glass figure often distorted by weight loss or pregnancy.   I recommend evaluation by a board certified plastic surgeon to learn about all the options.

The anatomy of the abdominal wall from the outside in consists of skin, fat, fascia, muscle, peritoneum, and intestinal cavity. The fascia actually envelops the midline abdominal muscles and is attached to the rectus muscles..

Whether anything is done to the fascia or not, the incision is carried down to the fascia. If the abdominal wall needs to be addressed, sutures are placed in the fascia to tighten it. These tightening sutures pull the abdominal muscles with it. These sutures are not used if the abdominal wall is not lax, (skin only tummy tuck).

The depth of the soft tissue elevation is usually at the level of the muscle fascia. Some go more superficial.

Regarding: 'Tummy Tuck Incision Depth
How deep are the incisions if you don't have to do any thing for the muscles or with the muscles?"

Tummy Tuck requires separation of the skin and fat of the tummy with exposure of the underlying muscles. Since the amount of fat comes in different thicknesses in different people the depth will vary from person to person.

Dr. Peter Aldea

The incision for a tummy tuck is carried down to the level of the muscular fascia whether there is any plication of the muscle or not.  There rarely is a reason to not perform the muscle plication.  Therefore this is something that you might wish to reconsider if this is your choice.

The tummy tuck incision is take right down to the outer surface of the muscles and then the abdominal wall is lifted up (undermined).