Objective: To determine work impact of chronic migraine (CM) versus episodic migraine (EM). Methods: Data were from the 2005 American Migraine Prevalence and Prevention study, a longitudinal population survey of more than 11,000 migraineurs. Lost productive time (LPT) was measured as missed work hours plus reduced productivity hour equivalents. Results: Those with CM were 19% less likely to be working for pay compared with migraineurs with ≤3 headache-days/month. On average, those with CM lost 4.6 hours/wk from headache compared with 1.1 hours for those with ≤3 headache-days/month. Those with 10 to 14 headache-days/month or with CM accounted for 9.1% of employed migraineurs, 20.8% of work-related LPT, and 35% of the overall lost work time when considering medical leave and unemployment. Conclusions: The work impact of CM and high frequency EM will be underestimated if employment status is not measured.