Mild traumatic brain injury (mTBI), with symptoms beyond 3 months, may be more common than previously believed, but is poorly understood. This has resulted in contradictory and confused information for service users, which has had an impact on those with mTBI and their families. This qualitative study aimed to improve understanding of the lived experiences of families of people with mTBI, with symptoms beyond 3 months. It extends a previous study, which focussed on all degrees of traumatic brain injury (TBI) (mild, moderate, and severe). Four individuals participated in semi-structured, virtual interviews. Following an interpretative phenomenological analysis (IPA), three superordinate themes were identified: (1) Going round in circles, (2) The second secondary impact, and (3) Dialogue with myself. Findings indicate that families of people with mTBI, with symptoms beyond 3 months, may experience many of the same challenges as families of people with moderate or severe TBI, albeit at a lesser intensity. This includes difficulty making sense of TBI and challenges to their identity, both of which mirror the comparator TBI study findings. However, findings also indicated that this group may experience different challenges to families of people with moderate or severe TBI, aspects of which have not previously been reported. Feelings of ambiguous loss may be increased by incongruity between information provided and families’ experiences, and by the varied availability and content of information. Implications for service providers are that consistent, transparent, and realistic information and education may aid adjustment and assist families to support people with mTBI.