Yes, underlayment is highly recommended when installing engineered wood flooring. A quality felt or foam underlayment acts as a moisture barrier, protects against minor subfloor imperfections, and adds sound insulation and cushioning underfoot. It also helps prevent moisture from being absorbed from the subfloor, which can cause the wood to warp or cup over time. Skipping underlayment may compromise the longevity and performance of your floor, especially in ground-level or concrete installations.