Career-planning courses are known to be effective career interventions for undergraduates, but their effect on developing alternate career plans was previously unknown. Forming alternate career plans increases the likelihood that students have viable career options available to them upon graduation because it encourages students to realistically consider multiple possibilities. Here we describe a one-term career-planning course developed in the context of an undergraduate biology curriculum. We assessed whether this course promoted development of primary and alternate career plans using a pre/post survey. We saw a significant increase in the percentage of students indicating they had plans aimed at achieving primary (increase of 37%) and alternate (increase of 48%) career goals from the beginning to the end of the course. Preliminary outcomes suggest that implementation of this course correlates with an increase in the percentage of students who indicate they have a job after graduation (increase of 16%). This type of course could be implemented in many other contexts to support career development in diverse fields.