Re-engaging patients who have fallen out of regular care is a challenge for all primary care practices, but especially for federally qualified health centers (FQHCs). We implemented and evaluated a system of proactive telephone and mail outreach within an FQHC serving a predominantly Latino and Spanish-speaking population for patients with diabetes who had not had a visit to the health center for at least six months. The primary study outcome was the proportion of patients who completed a follow-up visit within three months of the outreach. We also examined patient characteristics associated with completing a follow-up visit. Of 208 patients eligible for outreach, 24% (n = 49) completed a follow-up visit. Thirty-six percent (n = 74) had a disconnected or incorrect phone number, 16% (n = 34) were not reached within three phone call attempts, and 20% (n = 22) of letters mailed were returned to sender. Future efforts to re-engage patients in diabetes care should examine shorter intervals before outreach and other outreach strategies.