当个人面临由政策变化引起的工作激励的变化时，调整成本对他们有多重要?通过利用一项大幅增加工作激励的政策变化，我提供了对异质调整成本的第一个估计。政策变化提高了残疾保险项目的豁免门槛。我记录了对工作激励的强烈反应，因为我观察到过剩的数量â€- " "聚集"â€- "正好低于收入边际税较低的免税门槛。一个令人困惑的观察结果是，在政策改变后，个人继续聚集在前一个阈值。这一发现表明，在改变劳动力供给时，他们面临着调整成本。我使用新阈值和旧阈值处的聚类量来估计调整成本，调整成本随个人工作能力的不同而不同。能力较低的个体估计调整成本较高;从零到潜在收入的20%不等，平均为8%。收入相对于净税率â€(考虑异质调整成本â€)的估计弹性为0.2，是不考虑调整成本的估计弹性的两倍。 To investigate the relative size of the adjustment costs to the work incentives induced by the policy change, I evaluate the overall effect of the policy change on the labor supply using a Difference-in-Differences design. I find that individuals who already work, work more, and those who did not work, start working. Policies designed to increase labor supply will work if the induced work incentives are large enough to offset the adjustment costs. Accounting for adjustment costs then might explain disparate findings on the effects of an increase in work incentives on labor supply in disability insurance programs. These findings have important implications for designing policies and targeting heterogeneous groups to increase labor supply in disability insurance programs.