Contactless vital-sign estimation from video remains difficult because physiological cues are weak, spatially localized, and easily corrupted by illumination changes, motion artifacts, pose variation, and sensor noise. Existing methods typically learn deterministic mappings from video to physiological waveforms or rates, but they rarely model which visual evidence is reliable or when a prediction should be trusted. We propose a reliability-guided video token learning framework for uncertainty-aware physiological signal estimation. The framework learns to mine informative spatiotemporal tokens, suppress unreliable visual evidence, and infer structured physiological dynamics through masked video-token modeling, signal-guided alignment, and supervised vital-sign estimation. In addition to predicting physiological waveforms and rates, the model outputs an uncertainty score that reflects visual ambiguity and prediction reliability. We evaluate the framework across heterogeneous contactless sensing settings, including respiratory and rPPG benchmarks. In addition to standard accuracy metrics, we assess reliability using uncertainty separation, high-error detection, and risk–coverage analysis. Results show that explicit visual-evidence reliability modeling improves robustness across datasets and provides a practical confidence measure for contactless physiological monitoring.