Software maintenance and support costs account for up to 60% of the overall software life cycle cost and often burdens tightly budgeted information technology (IT) organizations. Agile software development approach delivers business value early, but implications on software maintainability are still unknown. The purpose of this quantitative study was to better comprehend the impact of the Agile development approach on software maintainability. The study drew on resource dependence and Lehman's software evolution theories. The research questions for the study examined (a) the impact of the Agile software development model on software maintainability and its components- software analyzability, changeability, stability, and testability; and (b) the extent of the influence of the Agile approach, characterized by test-driven development, refactoring, continuous integration (CI) on software maintainability and its components in U.S.-based IT organization. Software source code data from a specific project were collected from 61 software iterations of software system developed using the Agile model. The quantitative study employed the analytic hierarchy process and multiple regression technique for data analysis. Results of this study revealed that the test-driven development explained 17% of variation, whereas refactoring accounted for 11% of variation in software maintainability. The CI factor was found to be statistically insignificant. This study contributes to positive social change by ascertaining the impact of Agile approach on software maintainability, further benefiting the Agile project management, Agile advocates, IT operation management, Agile practitioners, businesses adapting Agile development approach, and by contributing to the possible reduction in software maintenance efforts and cost due to improved software maintainability. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]