State Residential Radon Disclosure, Testing, and Certification Requirements
State laws governing radon in residential real estate transactions vary dramatically. Some states require sellers to disclose known radon test results (Florida, Illinois, New Jersey). Others fold radon into broader environmental hazard disclosure forms (California, Colorado). Some mandate that radon measurement professionals be certified or licensed; others have no licensing requirement. EPA recommends 4 pCi/L as the action level but this is not a legal standard — state action levels may differ. This table gives the disclosure requirement, testing mandate, professional certification requirement, action level, and statute citation for each state.
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| jurisdiction | disclosure required | testing mandated | professional certification required | action level pci l | school testing required | statute citation |
|---|---|---|---|---|---|---|
| Alaska | Yes; part of a general residential real property disclosure statement. Form requires disclosure of knowledge of environmental hazards including radon gas. | No | No state-specific requirement | No state-specific action level; follows EPA recommended 4 pCi/L | No | Alaska Statutes §§ 34.70.010--.200 |
| California | Yes; part of a general environmental hazard disclosure form. Sellers of up to four residential units must disclose the presence of environmental hazards including radon gas. | No | Yes; no person may provide radon services for the general public unless that person has completed the National Radon Measurement Proficiency Program of the National Environmental Health Association or the National Radon Safety Board Certified Radon Professional Program | No state-specific action level; follows EPA recommended 4 pCi/L | No | California Civil Code §§ 1102--1102.18; California Health & Safety Code §§ 106750 et seq. |
| Colorado | Yes; sellers must provide buyers a state-developed radon pamphlet and disclose in writing any knowledge of radon concentrations, radon testing, or radon mitigation systems at the property. Landlords must also provide radon disclosure before lease signing. | Yes; schools must test for radon in accordance with AARST protocols. Newly constructed schools must test within 19 months of occupancy. Child care facilities must test within six months of occupancy. | Yes; state license required for individuals performing radon mitigation or radon measurement | 4 pCi/L | Yes; schools must test for radon in accordance with 2015 AARST Protocols and maintain results on file. Child care facilities must also test. | Colorado Revised Statutes §§ 38-35.7-112, 38-12-803, 12-165-101--113, 25-1.5-101 |
| Connecticut | Yes; sellers of residential property containing four units or fewer must provide a written residential condition report indicating seller's knowledge of any radon testing results and presence of a radon control system. | Yes; child day care centers and group day care homes using a basement or first-floor level must conduct at least one radon test during November through April. | Yes; Department of Public Health maintains a list of companies and individuals included in current lists of national radon proficiency programs. Radon mitigation contractors must have certification from NRSB or NEHA. | 4.0 pCi/L | Yes; boards of education must inspect and evaluate indoor air quality in schools annually, including radon levels. School building projects in areas of moderate or high radon potential must incorporate radon mitigation techniques. | Connecticut General Statutes §§ 20-327b, 19a-79, 19a-14b, 10-220, 10-291 |
| Delaware | Yes; sellers of property containing up to four residential dwelling units must disclose information about radon tests or inspections. Sellers must also provide purchasers with written information about radon developed by the state. | Yes; child care centers and homes must present evidence that the facility is free of radon hazards prior to licensing, with testing once every five years. | No state-specific licensing requirement for radon professionals | 4.0 pCi/L | No | Delaware Code, tit. 6, §§ 2570--2578; Delaware Code, tit. 14, § 3003a |
| District of Columbia | Yes; sellers of property containing up to four dwelling units must provide a real property disclosure statement including information about radon, asbestos, lead-based paint, and formaldehyde. | Yes; D.C. Dept. of General Services must assess D.C.-owned buildings including schools for radon and other IAQ risks. | Yes; persons conducting radon screening, testing, or mitigation for a fee must be certified by the National Radon Proficiency Program or the National Radon Safety Board. | No D.C.-specific action level; follows EPA recommended 4 pCi/L | Yes; D.C.-owned buildings including schools must be assessed for radon. | District of Columbia Code §§ 42-1301--1311, 28-4201--4203, 10-712 |
| Florida | Yes; a specified radon warning statement must be provided prior to the sale or lease of residential real estate. | Yes; radon testing required of all public and private schools, 24-hour care facilities owned or regulated by the state, and state-licensed day care centers in designated counties. | Yes; persons who perform radon measurement and mitigation must be certified by the Department of Health. | 4.0 pCi/L | Yes; all public and private schools in designated counties must be tested. | Florida Statutes § 404.056; Fla. Admin. Code r. 64E-5.1001, 64E-5.1201--1208 |
| Georgia | No state radon disclosure requirement in real estate transactions | No | No state-specific requirement | No state-specific action level | No | Georgia Code § 12-3-5 |
| Idaho | No state radon disclosure requirement in real estate transactions | Yes; children's residential care facilities must provide documentation of radon testing upon initial licensing. | No state-specific requirement | No state-specific action level | No | Idaho Statutes § 39-1210 |
| Illinois | Yes; sellers must disclose known elevated radon levels and provide buyers a state-developed pamphlet on radon testing and a general warning statement. Landlords must also disclose radon hazards to tenants. | Yes; licensed day care centers and homes must test for radon at least once every three years. All new residential construction must include passive radon-resistant construction techniques. | Yes; state licensing required for persons selling radon detection devices, performing radon detection, or performing radon reduction services. | State action level referenced but defers to EPA recommended 4 pCi/L | Yes; recommends that occupied school buildings be tested every five years for radon, with reporting to the Board of Education. | Illinois Compiled Statutes Ch. 420, §§ 44/1--90, 46/1--25, 52/1 et seq.; Ch. 765, §§ 77/1--65; Ch. 225, § 10/5.8; Ch. 105, § 5/10-20.48 |
| Indiana | Yes; sellers of property containing up to four dwelling units must complete a disclosure form disclosing knowledge of hazardous conditions including radon gas. | No | Yes; state certification program required for persons engaged in radon testing and abatement. | No state-specific action level; follows EPA recommended 4 pCi/L | No | Indiana Code §§ 32-21-5-1--12, 16-41-38-1--10 |
| Iowa | Yes; sellers must deliver a written disclosure statement indicating the condition of the property, including results of any radon tests. Buyer must acknowledge receipt of a state-issued radon fact sheet. | Yes; child care centers at ground level or with basements must test for radon. Public school districts must test by July 1, 2027 and every five years thereafter. | Yes; Department of Public Health certifies persons who test for radon and credentials persons who perform radon abatement. | 4.0 pCi/L | Yes; public school districts must test for radon by July 1, 2027 and every five years thereafter, and publish results on the district website. | Iowa Code §§ 558A.1 et seq., 237A.12, 280.32, 136B.1--.5 |
| Kansas | Yes; every contract for sale of residential real estate must contain a radon notice as specified in the law, including information about health effects and a recommendation for testing. | No | Yes; Department of Health and Environment certifies persons performing radon testing or mitigation. | No state-specific action level; follows EPA recommended 4 pCi/L | No | Kansas Statutes § 58-3078a; Kansas Statutes §§ 48-16a01 et seq. |
| Kentucky | Yes; Seller's Disclosure of Conditions form required in residential real estate transactions involving licensed agents, including disclosure of any radon testing and installed radon mitigation systems. | No | Yes; registration certificate required from the state to conduct radon measurement, mitigation, or laboratory analysis, with proof of NRPP or NRSB compliance. | No state-specific action level; follows EPA recommended 4 pCi/L | No | Kentucky Revised Statutes §§ 324.360, 309.430--.454 |
| Louisiana | Yes; sellers must complete a property disclosure document, with the form requiring disclosure of whether the property contains radon. | No | No state-specific requirement | No state-specific action level | No | Louisiana Revised Statutes § 9:3198 |
| Maine | Yes; sellers must provide a disclosure statement regarding known defects and presence of hazardous materials including radon. Landlords must provide written radon notice to tenants including test results and mitigation information. | Yes; residential landlords must have the air in their rental properties tested for radon, with re-testing every 10 years when requested by a tenant. | Yes; persons who test for or mitigate radon must register with the Department of Health and Human Services. | 4.0 pCi/L | Yes; school administrative units may test occupied schools every five years for radon. Newly-built schools must use radon-resistant construction techniques. | Maine Revised Statutes, tit. 33, § 173; tit. 14, § 6030-D; tit. 22, §§ 771--784; tit. 20-A, § 4013 |
| Maryland | Yes; sellers must provide buyers with a disclaimer or disclosure form including actual knowledge of radon and other hazardous materials. Home builders must also disclose environmental hazards including radon. | Yes; residential child care programs must maintain evidence that buildings have been tested for and found to be free of hazards from radon. | Yes; those engaging in the business of radon testing must complete certification by EPA's National Radon Measurement Proficiency Program. | No state-specific action level; follows EPA recommended 4 pCi/L | No explicit school testing requirement, but building code incorporates IRC Appendix F radon-resistant construction for Zone 1 counties. | Maryland Real Property Code § 10-702; Maryland Environment Code § 8-305; Maryland Public Safety Code §§ 12-503--504 |
| Massachusetts | No standalone radon disclosure requirement; state requires an informational brochure for home buyers on home inspections including information regarding radon inspections. | No | No state-specific requirement | No state-specific action level; follows EPA recommended 4 pCi/L | No | Massachusetts General Laws, ch. 13, § 97; ch. 43, § 93 |
| Michigan | Yes; sellers of residential property of up to four dwelling units must complete a seller's disclosure statement which provides for disclosure of radon gas and other environmental hazards. | Yes; child care homes must be tested for radon before initial license and every four years thereafter at license renewal. | No state-specific licensing requirement for radon professionals | 4.0 pCi/L | No | Michigan Compiled Laws §§ 565.951--.966, 722.112, 125.1504 |
| Minnesota | Yes; sellers must provide buyers with a copy of the Department of Health publication 'Radon in Real Estate Transactions' along with a written disclosure of radon test results, mitigation, and a radon warning. | No mandatory residential testing requirement | Yes; those who perform radon testing, mitigation, and laboratory services for compensation must be licensed annually by the state. | No state-specific action level; follows EPA recommended 4 pCi/L | No mandatory requirement; departments of health and education may develop a plan to encourage school districts to conduct radon testing. | Minnesota Statutes §§ 144.496, 144.4961, 326B.106, 123B.571 |
| Montana | Yes; sellers must provide a disclosure statement regarding adverse material facts including whether the property has been tested or treated for radon. Must also provide a general radon warning statement and disclosure of known radon test results. | No mandatory residential testing requirement | Yes; radon professionals must pass a U.S. EPA proficiency examination to be publicly listed as proficient. | No state-specific action level; follows EPA recommended 4 pCi/L | No mandatory requirement; school regulations recommend the use of radon prevention strategies in new construction. | Montana Code §§ 70-20-502, 75-3-601--607, 50-1-206 |
| Nebraska | Yes; sellers must submit a written disclosure statement disclosing knowledge of radon gas on the property, any radon mitigation conducted, and copies of any radon tests. | No mandatory residential testing requirement, but new construction intended to be regularly occupied must incorporate passive radon-resistant elements. | Yes; licensing required for radon measurement and mitigation specialists, technicians, and businesses. | 2.7 pCi/L (threshold for counties where radon-resistant new construction is required) | No | Nebraska Revised Statutes §§ 76-2,120, 71-3501, 76-3501--3507 |
| New Hampshire | Yes; prior to executing a contract for sale, sellers must provide buyers a radon notification statement about radon gas and testing. | No | Yes; those who design or install radon mitigation systems must be certified with the National Radon Proficiency Program or the National Radon Safety Board. | No state-specific action level; follows EPA recommended 4 pCi/L | No | New Hampshire Revised Statutes §§ 477:4-a, 310-A:189-a, 125:9 |
| New Jersey | Yes; sellers must provide buyers with copies of any radon test results upon entering into contract for sale. Disclosure form includes a voluntary section allowing sellers to provide radon testing results and mitigation information. | Yes; child care centers must be tested for radon at least once every five years. | Yes; state certification required for persons testing for or mitigating radon for remuneration. | No state-specific action level; follows EPA recommended 4 pCi/L | Yes; radon hazard subcode requires radon-resistant new construction in certain school buildings in designated areas. | New Jersey Statutes §§ 26:2D-70--80, 30:5B-5.2, 52:27D-123A--123E, 56:8-19.1 |
| New York | Yes; sellers of residential real property must complete and provide a property condition disclosure statement, including disclosure of any radon testing performed on the property. | Yes; child day care facilities in Zone 1 areas must complete radon testing before licensing. | Yes; radon testing and mitigation firms must report testing and mitigation results to the Department of Health. Radon Assessment Specialists must meet state requirements. | No state-specific action level; follows EPA recommended 4 pCi/L | No mandatory school testing requirement, but child day care facilities in Zone 1 areas must test. | New York Real Property Law § 462; New York Public Health Law § 225; New York Social Services Law § 390 |
| North Carolina | Yes; owners of residential real property of up to four units must provide buyers with a disclosure statement regarding environmental conditions including the presence of radon gas. | No | No mandatory certification; state established a voluntary approval process for radon proficiency programs in 2023. | No state-specific action level; follows EPA recommended 4 pCi/L | No mandatory requirement; legislature directed the State Board of Education to survey public schools to determine need for radon testing. | North Carolina General Statutes §§ 47E-1 et seq.; House Bill 782 (2023); House Bill 259 (S.L. 2023-134) |
| Ohio | Yes; sellers of residential real property of up to four units must deliver a disclosure form disclosing the presence of hazardous materials including radon gas. | No | Yes; state licensing required for persons providing professional radon testing and mitigation services. | No state-specific action level; follows EPA recommended 4 pCi/L | No | Ohio Revised Code §§ 5302.30, 3723.01--.18, 3748.20 |
| Oklahoma | Yes; sellers of residential property of 1-2 dwelling units must provide a Property Condition Disclosure Statement disclosing known presence of radon or any radon testing. | No | No state-specific requirement | No state-specific action level | No | Oklahoma Statutes, tit. 60, §§ 831--839 |
| Oregon | Yes; sellers of real property of up to four dwelling units must provide a seller's property disclosure statement including disclosure of any testing or treatment for radon gas. | Yes; school districts must develop a plan for radon testing in any frequently occupied room in contact with the ground, with retesting at least once every 10 years. | No state-specific licensing requirement for radon professionals | No state-specific action level; follows EPA recommended 4 pCi/L | Yes; school districts must develop a radon testing plan for frequently occupied rooms and retest at least once every 10 years. Schools must adopt a Healthy and Safe Schools Plan addressing radon. | Oregon Revised Statutes §§ 105.462--.490, 332.341, .345, 332.331, .334, .337, 455.365 |
| Pennsylvania | Yes; sellers must complete and deliver a Seller's Property Disclosure Statement disclosing knowledge of radon and other hazardous substances. | No | Yes; state certification required for persons who test for, mitigate, or safeguard a building from radon. | No state-specific action level; follows EPA recommended 4 pCi/L | No | Pennsylvania Statutes, tit. 68, §§ 7301 et seq.; tit. 63, §§ 2001 et seq.; tit. 35, §§ 7501--7504 |
| Rhode Island | Yes; sellers must provide buyers a disclosure form explaining all known deficient conditions including radon. Form must include a statement that radon exists in Rhode Island and testing is advisable. | Yes; state directs establishment of regulations requiring evaluation of all public buildings, schools, and day care centers for elevated radon levels. Child care facilities must test every three years. | Yes; state certification or licensure required for radon professionals. | No state-specific action level; follows EPA recommended 4 pCi/L | Yes; regulations require testing and notification of high radon levels in public buildings, schools, and child care facilities. | Rhode Island General Laws §§ 5-20.8-1--8, 23-61-1 et seq., 16-60-4 |
| South Carolina | Yes; sellers of property of up to four dwelling units must provide a written disclosure statement disclosing environmental contamination including radon gas. | No | No state-specific requirement | No state-specific action level | No | South Carolina Code §§ 27-50-10--110 |
| South Dakota | Yes; sellers must provide a property disclosure form addressing known hazardous conditions including radon and any known testing. | No | No state-specific requirement | No state-specific action level | No | South Dakota Codified Laws §§ 43-4-37--44 |
| Tennessee | Yes; sellers of residential real property of 1-4 dwelling units must provide a disclosure form disclosing knowledge of environmental hazards including radon gas. | No | No state-specific requirement | No state-specific action level | No mandatory requirement; encourages local education agencies to implement IAQ inspection programs that may address radon. | Tennessee Code §§ 66-5-201 et seq., 49-2-121 |
| Texas | Yes; sellers of single-unit residential property must give buyers a written disclosure notice addressing the presence of radon. | No | No state-specific requirement | No state-specific action level | No | Texas Property Code § 5.008; Texas Government Code §§ 2306.053, 2306.201 et seq. |
| Utah | No standalone radon disclosure requirement in real estate transactions; state requires radiation control agency to provide radon information with property tax notices. | No | Yes; those installing or repairing radon mitigation systems must be licensed as a contractor under state construction trades licensing law. | No state-specific action level; follows EPA recommended 4 pCi/L | No | Utah Code §§ 19-3-114, 58-55-305, 26B-7-116, 15A-3-206, 79-2-405 |
| Vermont | No state radon disclosure requirement in real estate transactions | Yes; public schools and approved independent schools must perform radon measurement by June 30, 2025 for any facility not tested in five or more years. | No state-specific requirement | No state-specific action level; follows EPA recommended 4 pCi/L | Yes; public and approved independent schools must perform radon measurement in accordance with ANSI/AARST protocols. | Vermont H. 426, Act 72 (2021) |
| Virginia | Yes; owners must disclose certain information to prospective purchasers using a state-developed form, including statements about radon zone location and advising purchasers to exercise due diligence regarding radon. | Yes; every school building must be tested for radon pursuant to EPA procedures. | Yes; radon screening, testing, or mitigation professionals must meet proficiency measures acceptable to the Board of Health or EPA, or obtain NRPP or NRSB certification. | No state-specific action level; follows EPA recommended 4 pCi/L | Yes; every school building in Virginia must be tested for radon pursuant to EPA procedures and regulations. | Virginia Code §§ 55.1-703, 22.1-138, 32.1-229, 32.1-229.01, 36-98 |
| Washington | Yes; sellers of improved and unimproved residential and commercial real property must provide a disclosure statement indicating knowledge of radon gas and other substances of environmental concern. | No | No state-specific requirement | No state-specific action level; follows EPA recommended 4 pCi/L | No | Washington Revised Code §§ 64.06.005--.070, 19.27.074 |
| West Virginia | No state radon disclosure requirement in real estate transactions | Yes; Division of Health must perform radon testing in new schools within one year of occupancy and at least once every five years thereafter. | Yes; state licensing required for radon testers, mitigators, and laboratories. | No state-specific action level; state must establish standards for safe levels of radon in public school buildings. | Yes; radon testing in new schools within one year of occupancy and at least once every five years thereafter. | West Virginia Code §§ 18-9E-3, 16-34-1 et seq. |
| Wisconsin | Yes; sellers of property of up to four dwelling units must provide buyers with a residential real estate condition disclosure report including the existence of radon. | Yes; family and group child care centers must be tested for radon gas levels in the lowest level used by children. | No state-specific licensing requirement for radon professionals | 4.0 pCi/L | No | Wisconsin Statutes §§ 709.001 et seq., 48.67, 254.34 |
Where this came from
Every record above links the page it was taken from and quotes the sentence that states it. These are the 1 source this dataset was assembled from.
- eli.orghttps://www.eli.org/sites/default/files/files-pdf/2025%20Radon.pdf
Machine-readable
- data.jsonThe whole dataset — every record with its source URL and source quote.
- Open Knowledge Format bundleOne JSON object per line — every record's frontmatter and quoted span exactly as it is held here, in one fetch.
- How this is made and checkedWhat "verified against source" does and does not mean.