An insertion system to precisely locate the insertion site for a sensor is disclosed. The insertion system includes an insertion guide with a protective layer, a guide layer and a liner layer. The protective layer is on top of the guide layer and the guide layer has a first locating structure and adhesive on the bottom. The liner layer is below the guide layer. The insertion system further includes an insertion tool with a corresponding first locating structure that interfaces with the first locating structure, wherein alignment of the first locating structure and corresponding first locating structure establishes placement of the insertion tool and subsequently the sensor.