Group identification predicts adherence to a group's norms, values, beliefs, and behaviors. The ability to accurately perceive another's degree of group identification may be important for predicting the other's beliefs and actions. In two studies, we examine friends' accuracy and bias in rating identification with social categories. Friends were asked to rate one another's and their own identification with state (Studies 1 and 2), national, and global citizen (Study 2) social identities. Across both studies, friends were shown to be both accurate and biased in rating one another's identification. Thus, although friends may project identification onto a friend (i.e., bias), friends are also able to accurately predict one another's degree of connection to social groups. Furthermore, friends' greater frequency of contact was found to increase accuracy in prediction. Together, the results provide initial evidence for future research examining person perception and intergroup interactions.