Third-party accreditations and certifications can provide legitimacy or signal trustworthiness about an organization and its products or services, and with very little exception, the vast majority of research on these labels focuses on their benefits. Yet the value of becoming accredited may change dramatically over time. Little research, if any, has examined the processes through which this occurs. Here, I develop theory about three mechanisms that could each tarnish the value of accreditation and reduce its performance impact. First, "quality patching" occurs when organizations are penalized if they seek accreditation shortly after problems occur, as observers believe such pursuits reflect superficial impression-management efforts. Second, "legitimacy dilution" occurs when the value of third-party accreditations becomes diluted as third parties certify more and more businesses. Finally, "stigma transfer" occurs when a newly accredited organization experiences spillover from quality problems at other accredited organizations. Empirical tests provide support for quality patching and legitimacy dilution but not for stigma transfer. Results suggest that organizations gaining new accreditations under some circumstances may benefit much less than organizations that gain those same accreditations under different circumstances.