This paper estimates the economic and non-economic returns to volunteering for prime-aged women. Estimates of a DCDP model indicate that an extra year of volunteer experience increases wage offers by 8.5% in future part-time work and by 2.6% in future full-time work. On average, working for free increases lifetime earnings by 16.7%. The economic returns to volunteering are more important than the non-economic returns in increasing lifetime utility. The model also reveals an adverse selection mechanism into volunteering that helps explain why reduced-form regressions of the returns to working for free will likely be downward biased.