Teacher labor markets are evolving across the United States. The rise of charter schools, alternative teacher certification, and portfolio districts are transforming teachers' access to employment, changing the way they search for and apply for jobs, and may also change the role that social networks play in the job search. However, we know little about how teachers use their networks to find jobs, particularly in increasingly fragmented local labor markets. We draw on interviews with 127 teachers in three districts chosen to reflect an increasing presence of charter schools: New Orleans, Detroit, and San Antonio. We find that the extent of fragmentation in a city's labor market drives the use of networks, with important implications for job access and equity.