Applicants may be able to avoid both duplicative radon testing and additional assessment of existing mitigation systems, if the existing system has an Operation, Maintenance and Monitoring (OM+M) plan under an appropriate ANSI-AARST standard (MAP Guide 9.6.3.2.).A radon professional could submit the OM+M plan along with maintenance records and ongoing testing results to HUD staff to document the existing system is functioning correctly and to request an exemption to the full radon report as per 9.6.3.2.C.1.