Placing V1298 Tau c into context with other young and mature exoplanets. Top: atmospheric metallicity vs. planet mass. The masses for V1298 Tau b and c are from J. H. Livingston et al. (2026). Bottom: bulk density vs. equilibrium temperature. We present systems with constrained ages in color and assume systems without ages are mature (>1 Gyr). Planets with lower limits on atmospheric metallicity are plotted in gray. Based on our observations, we speculate that the mass–metallicity relation evolves with planetary age due to early time atmospheric evolution. Additional observations are required to more robustly explore this trend. ✎