Radon Mitigation Cost

Guide

NRPP vs NRSB radon certification — what's the difference and which to hire

NRPP and NRSB are the two main radon mitigator certification bodies in the US. Plain explanation of how they differ, which states accept which, and why it matters less than you think.

NRPP (National Radon Proficiency Program) and NRSB (National Radon Safety Board) are the two private certification bodies that credential radon measurement and mitigation professionals in the US. Both are recognized by the EPA and accepted by all federal programs. Most state programs accept either — a few require state-specific licensing on top. For hiring purposes, either certification is fine. The difference matters mostly for the contractor, not for you.

How they differ

| Dimension | NRPP | NRSB | | --- | --- | --- | | Founded / administered | AARST (American Association of Radon Scientists & Technologists) | Independent board | | Certification levels | Measurement, mitigation, both | Measurement, mitigation, both | | Continuing education | 16 hours every 2 years | 16 hours every 2 years | | Exam fee | $300-$450 | $300-$450 | | Public registry | Yes, searchable by state/zip | Yes, searchable by state/zip | | Typical contractor cert holdings | Slightly more common nationally | More common in Northeast |

In practice both registries cover similar geographies; you may find more NRPP-certified contractors in some states and more NRSB in others, but every state has both.

State licensing on top

Several states require state-specific radon licensing IN ADDITION to NRPP or NRSB:

| State | State requirement | | --- | --- | | California | None (NRPP/NRSB only) | | Connecticut | DPH Radon Program license | | Florida | DOH Radon Program license | | Illinois | IEMA license | | Iowa | DPH license | | Kentucky | Cabinet for Health and Family Services license | | Maine | Radon Control Program license | | Maryland | MDE Radon Program license | | Massachusetts | DEP Radon Program license (Level 3+) | | Minnesota | MDH license | | New Hampshire | NH DES Radon Program license | | New Jersey | NJDEP license | | New York | NYS DOH Radon Program license | | Ohio | ODH license | | Pennsylvania | DEP certification | | Rhode Island | RIDOH license | | Vermont | VT DOH license | | Wisconsin | DHS support, not strict licensing |

For these states, verify the state credential too, not just NRPP/NRSB. A contractor working in PA without DEP certification is operating outside the law regardless of their NRPP standing.

How to verify a cert ID

Both registries are public:

  • NRPP: https://nrpp.info/find-a-pro/
  • NRSB: https://nrsb.org/services/find-a-radon-pro/

When a contractor gives you a quote, ask for their cert ID. Type it into the registry to confirm:

  1. Cert is current (not expired or suspended).
  2. Cert covers mitigation specifically (not just measurement).
  3. The name on the cert matches the company you're hiring.

This takes 30 seconds. Skip it and you may get a contractor whose cert expired 18 months ago, which voids any state-program rebate you were planning to claim.

Why does the cert actually matter?

Three reasons beyond "looks legitimate":

  1. State program eligibility. Many state rebate programs only pay claims from certified mitigators.
  2. Insurance + warranty. Many home warranties exclude radon work performed by uncertified contractors.
  3. Real estate disclosure. Mitigation done by certified contractors satisfies state real-estate disclosure laws. DIY or uncertified work does not.

What if my contractor is only certified through one body?

Fine. Both are EPA-recognized. The choice of NRPP vs NRSB is the contractor's own business decision — they pay annual fees to their preferred body and hold the related continuing education.

What if my state doesn't require licensing AND my contractor isn't NRPP/NRSB certified?

Walk away. Even in states without licensing requirements, NRPP/NRSB membership signals the contractor takes industry standards seriously. An uncertified mitigator may install a non-compliant fan, vent the discharge into the eaves instead of above the roofline, or skip the manometer that lets the homeowner verify the system is running.

The cert verification step is the only step most homeowners skip and it's the highest-leverage 30 seconds you can spend before signing a mitigation contract.

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