While there is a strong research base that supports intervening early in mathematics, research investigating the importance of mathematics vocabulary is still emerging. Practitioners and researchers may benefit from understanding how mathematics interventions support mathematics vocabulary acquisition, particularly for students who struggle with learning mathematics. Thus, the purpose of this study was to conduct a mathematics vocabulary content analysis across seven kindergarten and first-grade mathematics interventions. Across the intervention lessons, we recorded suggested teacher and student actions related to mathematics vocabulary instruction. The results indicated the most common instructional strategies used to teach mathematics vocabulary include: providing students with the opportunity to apply the meaning of the vocabulary term (94.7%), using representations (66.4%), and asking students to respond to teacher prompts using the term (44.7%). Overall, 29.7% of lessons clearly defined vocabulary terms, and 5.8% of lesson objectives addressed teaching the definition of the term. We discuss implications for researchers and practitioners to supplement interventions with opportunities for students to learn, practise, and apply mathematics vocabulary.