Capitalist ideas of productivity became central to medicine under slavery. They shaped how physicians treated enslaved patients, crafted a scientific basis for medicine, and conceived of themselves as professionals. Between the late-eighteenth-century and the mid-nineteenth-century, white male physicians in Louisiana and Cuba distinguished themselves from other healers: first, by aligning with Spanish colonialism, and then, by making themselves essential to a new form of plantation management that used clock-time discipline, hierarchical divisions of labor, and complex accounting systems. These technologies helped planters track the hours and days each enslaved person spent working, eating, sleeping, birthing, suffering from sickness and injuries, and recovering. This in turn enabled precise interpretations of enslaved health in terms of productivity, which was primarily measured in work time and the number of commodities produced. Physicians, who were seeking a rigorous intellectual foundation for medical knowledge production, latched onto planter methods of calculating and controlling enslaved health. One of those methods was what planters and physicians called “sick time,” which was an allotment of time away from work intended to manage illness enough for enslaved people to return to work. However, as physicians used plantation management to cast an air of scientific accuracy over their knowledge, enslaved people reconfigured their own medical practices to make themselves less visible and countable. Fugitive practices involving trees, animals, and natural springs helped enslaved people to heal by taking their own forms of sick time.