Introduction: Both police and Armed Forces personnel are at increased risk of encountering psychological trauma with the prevalence of mental health problems higher than in the general population. Appropriate and effective mental health services are crucial but there is a marked lack of take-up of services. This research considered how the attitudes of police officers with a military background affected their help-seeking for mental health problems.Methodology: A phenomenological approach was used with the aims of producing rich data with the insider viewpoint and generating theory about the process. Semi-structured interviews were conducted with 11 male ex-Armed Forces police officers. A social constructivist Grounded Theory approach was used to analyse the data.Findings: Police officers with an Armed Forces background viewed themselves as a discrete social group. There was significant cognitive separation between them and their non-service peers, the police organisation, those with mental illness and mental health services. Four group norms, formed during military service, were identified as relevant to the research topic: a) Mission Focus, b) Strength and Control, c) Cohesion and d) Be the Best. These norms were used to determine the stigma associated with both on-set and off-set responsibility for mental health problems within the group. Group norms underpinned the acceptable strategies for managing mental health problems. Education around mental health was not seen as personally relevant at the time. Accepting a mental health problem was the greatest barrier to care and meant an acceptance of norm violation in oneself often triggering an existential crisis. Potential helpers were judged against the group norms and this either hindered or facilitated the process. As the individual recovered, they reframed the group norms in relation to their experience of mental illness and reported Post Traumatic Growth. A theoretical model for the help-seeking process is proposed.Implications: Anti-stigma interventionists need to consider the individual's perception of their loss of a valued identity and their violation of group norms. The stereotyping and generalisation of police managers and mental health services as "other" reduces the likelihood of accepting offers of support from those sources. Education must connect with the early beliefs from military service in order to effect change. Organisational denial or ambivalence about the subject needs tackling just as much as the denial in the group and individuals. The group holds much of the solution to the problem within its own membership and peer supporters who have overcome their own mental health challenges can be better used by the organisation to both prevent and manage the problem. They need to able to provide timely, trusted referrals to competent mental health services.