Devolution is generally defined as a process of transfer of political, administrative and fiscal management powers between central government and lower levels of government, primarily operating at city and region levels (Potter, 2001). The essence of devolution is to bring services closer to the citizens. Performance of the County Government s depends on the kind of workforce they have. Performance can be affected by many factors, career stagnation being one of them. Indeed, scholars have noted that it is inevitable for employees to react to career plateau with bad performance and loss of motivation and commitment. This comes from believes that, upward movement is the benchmark to measuring performance and therefore in the absence of this, the employees become demotivated (Jang and Tak, 2008; Burke and Mikkelsen, 2006; Tremblay and Rogers, 2004). The literature reviewed has provided information on effects of career stagnation on performance elsewhere in the world by giving a global view. It is therefore recognized that this area of study still remains largely un-explored, shown by the fact that literature on career plateau in Kenya is lacking, yet the subject has a global attention evidenced by a wide array of scholars who have written on it. The research has not been conducted in Murang’a either. It is against this background that the study sought to establish the effects of career stagnation on performance in Murang’aCounty Government. The overall objective of the study was to establish the effects of employee career stagnationon performance in the civil service, a case study of Murang’aCountyGovernment. Specific objectives were: Establish the effects of employee career stagnation on job performance inMurang’aCounty Government , establish the relationship between work related stress and job performance inMurang’aCounty Government , establish effect of motivation on job performance in Murang’aCounty Government , establish the relationship between individual skills and abilities and job performance in Murang’aCounty Government , establish the relationship between lack of an innovative climate and job performance in Murang’aCounty Government. The study was guided by three theories: - the attributory theory, Donald Super’s career model theory and the three factor model theory. The study adopted a survey research design. Descriptive analysis involved the use of frequencies in their absolute and relative forms (percentage). Inferential analysis was done to find out if there is any relationship between dependent and the independent variables of the study .The target population was 354 employees. The research adopted stratified random sampling design and the sample size was 178. The response rate 84% hence reliability and validity of the study. The R value of the study was 0.964 and R2 value of 0.926. This indicates that skills and abilities to perform, motivation, an innovative climate, work stress all influences career stagnation in Murang’a County government by 92.9%. The study findings suggest there is a positive correlation between all components of career plateau with a significance of 0.875 for lack of skills and abilities, 0.860 for lack of an innovative climate, 0.855 for lack of motivation and last but not least 0.659 for work related stress levels. The study concludes that the general performance of CountyGovernment has been affected by lack of necessary skills, work related stress, lack of innovative climate and lack organizational career orientation among staff members. The study recommends training of employees to equip them with necessary skills, create an innovative climate, ensure career orientation is done to all employees and work related stress in kept to the minimum. The research may be of significance to human resource practitioners within and outside Murang’aCounty in managing career stagnation.