Mentoring is important to career development and employee morale of public sector employees, but little is known about how employee mentoring needs change over the course of one’s career or at different job classification levels. An online survey about the mentoring needs of 251 aquatic professionals in the USDA Forest Service was conducted in 2019. Quantitative data were analyzed across three federal employee grade levels and four career stages. This study found that grade levels influenced the type of skills employees seek to develop and the attributes associated with successful mentoring. Employees in lower grade positions believed that mentoring would help them to achieve a faster promotion or prepare them for a new position, but they also had less access to mentors and received the least encouragement from their supervisors to seek mentoring. Employees at all career stages believed that mentoring was valuable to their professional growth, while middle- and late-career employees received less encouragement from their supervisor to seek a mentor. Differences in mentorship needs, access, importance, and structures across career stages and grade levels suggest potential areas of future development or intervention to expand the benefits of mentoring to all employees.