Absolutely. New construction in Ohio Zone 1 areas should test within 90 days of occupancy. Many builders now install passive radon vent stacks; activating one (adding a fan) is the cheapest path to mitigation if levels test high.
More detail
Ohio adopted residential code amendments incorporating radon-resistant new-construction (RRNC) appendix-F provisions for designated Zone 1 counties, which means most homes built in Hamilton, Butler, Warren, and Clermont since roughly 2010 have a passive 4-inch PVC vent stack stubbed through the slab and routed up through the home. RRNC is a passive mitigation strategy: the stack relies on stack effect alone to vent radon. In Cincinnati climate it modestly reduces levels but rarely brings them below 4.0 pCi/L without an active fan. Builders are not required to test or warrant the post-construction radon level, so new-home buyers should plan to test within 90 days of move-in. If the test reads above 4.0 pCi/L, the existing passive stack is the foundation for a fan-activation install at $700-$1,200 (much cheaper than installing a new system from scratch on a home without RRNC provisions). Cincinnati builder pattern: most Mason, West Chester, Loveland, and Liberty Township builders include passive radon stacks per Ohio RRNC code as standard, but rarely test the completed home unless the buyer requests it. Buyers should add radon testing as a contingency in any new-construction purchase contract; the builder is generally not obligated to mitigate post-occupancy unless contracted up front.