This qualitative study explored reasons K-6 teachers did or did not engage students regularly in writing. Interviews with 14 teachers, classified as high, transitional, and low implementers of writing instruction, revealed three themes: hindrances and helps, beliefs concerning practice, and preparation and professional development. Both high and low implementers identified time constraints, varying student needs, and tensions between content and conventions as hindrances, but dealt with them differently. High implementers reported receiving help from mentors, unlike low implementers. High implementers valued writing as a process and viewed themselves as good writers. They scaffolded students' writing and integrated writing with content. Low implementers valued writing but did not view themselves as good writers. High and low implementers viewed university courses and professional development differently.