Yes. Any foundation work, sump pit modification, or significant air-sealing changes the radon equilibrium in your home. Retest within 30-90 days of finishing work.
More detail
Radon equilibrium in a home is sensitive to changes in air pressure dynamics. A finished basement with new drywall, sealed-and-insulated rim joists, replaced HVAC, or a new sump-pit configuration has a different air-flow profile than the unfinished basement that was last tested. Sometimes mitigation improves; sometimes it worsens. Common outcomes after a remodel: rim-joist sealing reduces overall infiltration but increases stack-effect pull on the basement, raising radon. Or vice versa: a new HRV/ERV introduces fresh air, lowering levels. The only way to know is retest. Allow 30-90 days for the home to reach a new steady state before testing; same-week post-remodel readings are unreliable. If a mitigation system is already installed, retest with the system running normally; do not turn it off for the test. Specific Cincinnati examples that warrant retest: any waterproofing project (interior drainage system or exterior excavation), any sump-pit installation or replacement, any major basement-finish project that adds a vapor barrier or significant new sealing, and any rim-joist insulation retrofit or basement-wall foam application. Even projects that seem unrelated to radon (a furnace replacement that changes draft characteristics, a new exhaust fan in a basement bath) can shift the equilibrium meaningfully.