Digital accessibility of e-learning provides an opportunity to fully participate in the educational process for all students, including persons with disabilities. Each specialist involved in the development of e-learning content and resources should be competent in digital accessibility and universal design. The authors propose a methodological approach to the development of digital accessibility competencies and present the results of testing this approach in practice. In 2021, on the basis of one of the Russian universities, a methodology for the formation of digital accessibility competences was developed and tested, including a system of competences, tools for testing formed competences, a curriculum and an appropriate online course. In addition, a study sample was formed (177 undergraduate and graduate students), a training course was conducted, and training outcomes were analyzed. It is for the first time that a methodological approach to the formation of digital accessibility competences has been proposed in the Russian Federation. The training outcomes confirmed the efficiency of the proposed approach: 96% of the students successfully completed the training, of which more than 67% achieved intermediate and advanced levels of the competences. A significant positive correlation was found between the successfully completed current tasks and the results of the final tests of self-assessment and formal assessment. It was shown that the training efficiency did not depend on how (voluntarily or compulsorily) the students were enrolled in the course, whether there were pedagogical disciplines in their curricula and what was the level of their university education. The relationship found between the results of final self-assessment and the results of formal assessment can be interpreted as consistency between satisfaction with the training and its success. The developed methodological tools, including the online course, can be used for the professional training of teachers, the formation of professional competences of IT specialists as well as the improvement of the overall digital literacy of specialists involved in the development of digital content.