The unfolded protein response (UPR) regulates the endoplasmic reticulum (ER) protein folding capacity by sensing unfolded proteins in the ER lumen and initiating a transcriptional program to restore homeostasis. Using electron microscopy, the authors found that yeast cells expand their ER volume by at least 5-fold under UPR-inducing conditions. Surprisingly, they discovered the formation of autophagosome-like structures that are densely packed with membrane stacks derived from the expanded ER. This ER-specific autophagic process, which they term ER-phagy, utilizes several autophagy genes that are induced by the UPR and essential for cell survival under severe ER stress. Notably, cell survival does not require vacuolar proteases, suggesting that ER sequestration into these structures rather than their degradation is crucial. The authors propose that ER-phagy helps cells maintain a new steady-state level of ER abundance in the face of continuously accumulating unfolded proteins.The unfolded protein response (UPR) regulates the endoplasmic reticulum (ER) protein folding capacity by sensing unfolded proteins in the ER lumen and initiating a transcriptional program to restore homeostasis. Using electron microscopy, the authors found that yeast cells expand their ER volume by at least 5-fold under UPR-inducing conditions. Surprisingly, they discovered the formation of autophagosome-like structures that are densely packed with membrane stacks derived from the expanded ER. This ER-specific autophagic process, which they term ER-phagy, utilizes several autophagy genes that are induced by the UPR and essential for cell survival under severe ER stress. Notably, cell survival does not require vacuolar proteases, suggesting that ER sequestration into these structures rather than their degradation is crucial. The authors propose that ER-phagy helps cells maintain a new steady-state level of ER abundance in the face of continuously accumulating unfolded proteins.