Parental traumatic brain injury (TBI-P) and the effect it has on adolescents living in the home has been mostly avoided in the current literature. Even more rare in the literature is the idea of ambiguous loss, coined by Boss (1991). An ambiguous loss refers to a loss of someone who has not died, but who is also not the same person as before the injury, physically or mentally. Consequently, the loss is unclear and requires constant recalibration by the uninjured family members to accept their ever-changing injured family member. Together, no researcher has ever studied ambiguous loss as it relates to TBI-P. This study focused on three research questions: Research Question 1: As it pertains to TBI-P, what is the influence of ambiguous loss when experienced during adolescence? Research Question 2: When TBI-P is experienced in adolescence, how does the perception of ambiguous loss result in tangible consequences later in life? Research Question 3: In what ways do adolescents experiencing ambiguous loss from TBI-P describe their family, self, and situation? Using a qualitative approach, this phenomenological dissertation found four primary findings. First, adolescents can experience feelings of ambiguous loss. Second, the time since the injury can affect the severity of feelings of ambiguous loss in adolescents with older participants reporting more feelings of loss. Third, adolescents can experience tangible outcomes as they relate to TBI-P during their adolescence and into adulthood. Finally, ambiguous loss can affect the self-perception of adolescents.