Difficulties falling asleep, staying asleep, waking too early, and daytime dysfunction are prevalent in insomnia disorder. Insomnia-related complaint crossed with sleep data yields complaining good sleepers (CG) and complaining poor sleepers (CP). Many theories relate to the development and maintenance of insomnia disorder. Little is known about factors influencing an insomnia identity, the self-ascribed belief that one has insomnia, or that differentiate these groups. We evaluated insomnia identity severity and differences between treatment-seeking groups on factors related to one’s sleep experience and sleep parameters. An insomnia complaint was considered evidence for an insomnia identity; however, the final sample yielded an unexpected group who did not endorse insomnia identity. Therefore, participants were also classified via insomnia identity yielding insomnia identifying good sleepers (IIG), insomnia identifying poor sleepers (IIP), and participants without insomnia identity (WOII). Participants provided demographic information, medical and psychiatric diagnoses, information related to their insomnia complaint, and two weeks of daily sleep diaries. CG and CP were evaluated on differences between perceived sleep comparisons, restorative sleep, daytime impairment, and insomnia-related catastrophizing. There were no significant differences on any factors for ? < .05. IIG, IIP, and WOII were evaluated on differences for the same four variables. A statistically significant difference emerged among groups on restorative sleep, F (2, 60) = 3.83, p = .03. Post hoc testing revealed that restorative sleep ratings were significantly higher in IIG compared to IIP, but not WOII (p = .02). Multiple linear regression tested the four sleep variables and self-reported sleep parameters as predictors of insomnia identity severity. The overall model was significant, F (1, 61) = 5.21, p = .03, R2 = .08. The analysis was conducted again substituting the three subfactors of catastrophic thinking to determine the effect of each subscale. The overall model was significant, F (1, 61) = 7.55, p = .008. R2 = .11. Negative sleep comparisons and increased helplessness predicted a stronger conviction of insomnia identity. Restorative sleep significantly differentiated IIG, IIP, and WOII, perhaps reflecting differences in sleep status rather than insomnia identity. Implications of results and further study directions on insomnia identity are discussed.