HUD's Notice CPD-23-103 sets the department's radon policy, and it says what it is not: the notice 'does not impose radon testing requirements', it 'applies only to projects that are subject to' HUD's contamination regulations at 24 CFR 50.3(i) or 24 CFR 58.5(i), and 'it does not apply to the purchase of single family homes with an FHA-backed mortgage nor Section 184 and Section 184A loan guarantees'. HUD's older single-family reference guide said the same in one line: 'HUD does not require radon testing of homes that are being insured under the FHA mortgage insurance program'.
Where HUD's policy does reach is the environmental review of its assisted and insured projects. The notice's own table lists FHA-insured multifamily loans and FHA-insured healthcare loans, HOME, Community Development Block Grant and Continuum of Care projects among the programs it applies to, and HUD's FAQ on the policy allows DIY test kits for single-family buildings of one to four dwelling units in those projects, since they 'are very affordable and should work with project budgets of all sizes'.
VA's rule changed in 2026. Chapter 12 of the VA Lenders Handbook, Pamphlet 26-7, in the version in force until May 1, 2026, said 'VA recommends testing for radon gas' on the Notice of Value a Veteran receives with the appraisal, and on new construction the builder had to certify that radon-resistant techniques were used where applicable, which VA tied to
A loan rule says nothing about the house. EPA's Citizen's Guide estimates that nearly 1 out of every 15 homes in the U.S. has an elevated radon level and notes that high radon levels have been found in every state, so the test is worth doing whichever loan pays for the home.
What to do next: test the lowest lived-in level before closing if you can, read the result with the interpreter, and look up your state's radon program for any disclosure rule that applies to the sale.