H.R. 4861 — Working Waterfront Disaster Mitigation Tax Credit Act

This section establishes a new nonrefundable tax credit under new IRC §48F equal to 30% of a taxpayer's qualified investment in eligible depreciable property placed in service as part of a qualifying working waterfront disaster mitigation project. Qualified investments exclude amounts attributable to qualified rehabilitation expenditures under IRC §47 and are subject to (1) a $300,000 annual limit per taxpayer (with aggregation rules under IRC §§52 and 414 and inflation adjustment after 2026 using a 2025 base year, rounded to the nearest $10,000), and (2) ineligibility if the taxpayer received a credit under this section (other than for qualified progress expenditures) within the prior 10 taxable years. A qualifying project must comply with specified International Code Council building codes (2021 edition for projects placed in service before 2033; most recent Secretary-affirmed code thereafter) and incorporate one or more natural hazard mitigation measures—such as structural elevation, flood risk reduction, shoreline stabilization, floodproofing, retrofitting, or warning systems—for working waterfront property. (Thus, the credit incentivizes private investment in resilience upgrades for commercial waterfront infrastructure vulnerable to floods, erosion, storms, and other disasters.)