Rationale, aims and objective: Accrediting health care organizations against standards is a recognized safety and quality intervention. The credibility of an accreditation programme relies on surveying reliability. We investigated accreditation survey coordinators’ perceptions of reliability issues and their continued relevancy, during a period of national accreditation reform. Method: In 2013 and 2014, questionnaire surveys were developed using survey coordinators’ feedback of their experiences and concerns regarding the accreditation process. Each year, a purpose-designed questionnaire survey was administered during the accrediting agency survey coordinator training days. Results: Participants reported that survey reliability was informed by five categories of issues: the management of the accreditation process, including standards and health care organizational issues; surveyor workforce management; survey coordinator role; survey team; and individual surveyors. A new accreditation system and programme did not alter the factors reported to shape survey reliability. However, across the reform period, there was a noted change within each category of the specific issues that were of concern. Furthermore, consensus between coordinators that existed in 2013 appears to have diminished in 2014. Across all categories, in 2014 there was greater diversity of opinion than in 2013. Conclusions: The known challenges to the reliability of an accreditation programme retained their potency and relevancy during a period of reform. The diversity of opinion identified across the coordinator workforce could potentially place the credibility and reliability of the new scheme at risk. The study highlights that reliability of an accreditation scheme is an ongoing achievement, not a one-off attainment.