We conducted focus groups and individual interviews in a diverse population of parents to qualitatively explore preferences and readiness for text message immunization reminders. We used content analysis to review and independently code transcripts. Text message reminders were well-accepted by parents; many thought they would be more effective than standard phone or mail reminders. Parents preferred text message reminders to be brief and personalized. Most parents were able to retrieve sample text messages but many had difficulty with interactive texting.