Michigan's alternative-route certification option allows candidates to complete an expedited teacher preparation program while simultaneously working as a teacher of record under an Interim Teaching Certificate (ITC). This brief examines how the use of ITCs in Michigan has evolved as alternative-route TPPs expanded throughout the state. We combine publicly available state- and program-level data with Michigan teacher certification and public school employment records to explore the following questions: (1) Where and how have alt-route certification pathways been expanding? We show that recent rebounds in Michigan's TPP enrollment are driven by alt-route programs, with the largest increases coming from two relatively new virtual programs. While historically concentrated in urban areas, alt-routes are becoming more prominent in rural areas and suburbs and are adapting to meet the unique staffing needs of those areas; (2) How do alt-route programs contribute to educator diversity? The teachers who enter the workforce through alternative certification pathways are more diverse than those from traditional TPPs. State-level trends suggest that alt-routes are less diverse than they used to be, but we find that this is because they are expanding into areas of the state with less diverse populations. This expansion is helping to bring more teachers of color to rural and suburban school districts; and (3) Are alt-route teachers more likely to leave the profession? We find that early-career teachers from alt-route programs exit the profession at higher rates than traditional-route teachers with the same level of teaching experience. Additional support for alt-route teachers may be necessary for these programs to make a lasting effect on Michigan's teacher workforce.