This study examines a 30-item Spanish elicited imitation task (EIT) as a measure of global language proficiency for heritage language (HL) learners of Spanish. Results from Rasch modeling suggest that, while EIT scores demonstrated excellent reliability, the ability of much of the HL sample far exceeded the difficulty of the items. Differential item functioning analysis revealed that several items functioned differently for the present study's HL sample than for the second language learners from a prior study. Additionally, although EIT scores were strongly correlated with another proficiency measure for the present HL sample (e.g., the Diploma de español como lengua extranjera or DELE), common-person equating suggested that the EIT and the DELE may measure different latent variables. Overall, the results provide evidence of the EIT's utility as a proficiency assessment tool for research on HL learners, however, with limitations and the need for additional analyses discussed.