How does public authority maintain their legitimacy in society? According to theory of institutional adjustment they maintain their authority by adapting to different criteria and modern trends society. One most famous social trend in Sweden has for the last decades been NPM, which shortly means adjusting the organization by making it more like the private sectors companies. This could mean adjusting the entire organization or just taking small influences. Large institutions in the public sector are by mostly related to something rigid and unchanging, but the research declares that even large institutions adapt their structure to maintain legitimacy. This means they only partly change the formal administration to be presented to the public but remain the same in informal structures. Research also tells that some administrations partly change by adjusting the trends to their specific purpose and profession. Riksdagsförvaltningen is the public administration of the Swedish Parliament and is one of the largest institutions in Swedish public sector. The question of this thesis is how does Riksdagsförvaltningen as an institution with such closeness to the political structure of parliament adapt to modern trends or why not? Could the institutional adjustment be affected by its purpose and profession? In this thesis managers in Riksdagsförvaltningen have been interviewed for investigating this question in a qualitative content analysis. The conclusion is that Riksdagsförvaltningen may adjust their formal administration while the mentality and organizational culture of the institution remain the same. It also adapts specific trends to fit its purpose by remaining as a traditional bureaucracy and bringing in ideals from NPM. The closeness to the parliament creates a complicated situation to both pleasure the members of parliament and maintain the values of the administration.