Research suggests that Mindfulness Training (MT) is helpful for dealing with depression, anxiety, and pain. Yet MT has become so popular that it seems like it is recommended for everything, ranging from parenting to dieting to corporate success. Yet without research that identifies the critical features of successful MT, we can’t effectively judge these emerging MT products and courses. Our project investigates the cherished assumption that formal meditation practice is necessary for MT benefits. While the need to actually sit and meditate seems to be an obvious MT requirement, we know little about how much practice is needed to promote training benefits, both during and following training programs. Especially absent is evidence of what is required for MT to improve social function. To address these issues, we will recruit a large sample of participants enrolling in MT courses. These participants will provide daily reports on practice, stress, and social function, both during the course and over a four month follow-up period. From this study, we hope to identify ‘minimum dose’ criteria for realizing and maintaining MT benefits. Such criteria are critical for preserving MT efficacy even as it grows in popularity, allowing for the responsible proliferation of these promising training techniques.