Radon Contractors in Maryland

Ask specifically whether the contractor is certified by the NRPP (National Radon Proficiency Program) or NRSB (National Radon Safety Board). These are the two EPA-recognized programs. A legitimate pro will have a certification number they can give you.

Mitigation system costs vary. A typical sub-slab depressurization system runs $800–$2,000 depending on home size, foundation type, and labor rates in your area. If a quote is dramatically lower, ask what's included.

Any reputable contractor will do a follow-up radon test after installing a mitigation system to confirm it's working. If they don't offer one, ask for it explicitly. You should see levels drop to below 2 pCi/L in most cases.

Star ratings are a useful filter, but read a few actual reviews. Look for mentions of professionalism, whether they explained what they were doing, and whether the follow-up test came back clean. Those details tell you more than the number.