This paper presents a computer-aided design tool, IPRAIL, which automatically retargets existing analog layouts for technology migration and new specifications. The reuse-based methodology adopted in IPRAIL utilizes expert designer knowledge embedded in analog layouts. IPRAIL automatically extracts analog circuit and layout intellectual properties as templates, incorporates new technology design rules and device sizes, and generates fully functional layouts. This is illustrated by retargeting two practical operational amplifier layouts from the TSMC 0.25um CMOS process to the TSMC 0.18um CMOS process. While manual re-design is known to take days to weeks, IPRAIL only takes minutes and achieves comparable circuit performances.