There are a few ways to mitigate a home. The most commonly used are Sub Slab and Crawlspace Depressurization Systems.
With a Sub Slab System, a hole is cut through the concrete slab and a cavity is formed in the soil beneath the hole. A PVC pipefitting is then set into the hole and attached to the depressurization system. The depressurization system creates a vacuum under the slab, this vacuum causes Radon as well as other soil gasses, to move towards the suction point where it is collected and exhausted safely above the home.
In a crawlspace application, a perforated pipe is laid throughout the space and then covered with a high-density plastic which is sealed to the foundation. This creates a vapor barrier. When the depressurization system is connected to the perforated pipe under the barrier the soil gas is collected and exhausted safely above the home