Within a two-year urban teacher residency program at [University], which focuses on training high school teachers to incorporate computational thinking (CT) into STEM education with an emphasis on equity, this study delves into how these preservice teaching residents (TRs) understood and applied CT in high school STEM settings. Based on our initial thematic content analysis of ten 30-minute artifact-based interviews, teachers’ understanding and application of CT could be categorized in two ways: 1) One group of teachers showcased clear, explicit knowledge of CT and actively incorporated it into their instruction; 2) Another group, despite their evident understanding of CT, subtly and implicitly integrated CT into their teaching methods. Our findings suggest that while TRs may differ in whether they explicitly or implicitly integrated CT into their lesson plans, their comments suggest that they have foundational understandings and hold values that suggest they can build upon them. The TRs held definitional understandings of CT and had intentions to design and teach with CT integration, explicitly, or more commonly, implicitly. All of the TRs recognized opportunities in their lesson plans for teaching CT to students, which suggests the potential for more explicit integration in the future. These insights guide our subsequent efforts in teacher training, ensuring educators are equipped to weave CT into STEM lessons. Our findings contribute to a growing body of work that seeks to build strong preservice teaching practices, as they learn to translate CT knowledge into effective teaching practices while working towards higher levels of CT integration.