Technical Abstract: A 2-year study was conducted to evaluate fingerling to stocker (phase 2) and stocker to growout (phase 3) of three phases of a modular production system for channel catfish in commercial-scale ponds. Fingerlings (mean = 14.3 kg/1000, 11.9 cm) were stocked into each of six earthen ponds (1.62 ha) at a density of 123,500/ha and fed a 35% crude protein floating feed daily to satiation. After 142 days, the mean weight of harvested stockers ranged from 108.9 to 158.8 g and survival ranged from 38.8% to 62.0%. These fish were subsequently stocked at either 12,350/ha or 16,055/ha, into1.62 ha ponds for growout to foodsize fish (=567.5 kg), and fed a 35% crude protein floating feed to satiation. A partial (selective) harvest (105 to 130 days post-stocking) using an in-pond grader, and a final harvest (207 to 245 days post-stocking) were conducted. Combined production means were 7,124 kg/ha and 7,210 kg/ha for the 12,350/ha and 16,055/ha treatments, respectively. Survival (range = 84.3% to 105.5%) and feed conversion ratios (range = 2.25 to 2.65) were not significantly different. Mean weight (659.5 g) and length (41.8 cm) of fish harvested from the 12,350/ha treatment ponds were significantly higher those of fish harvested from the 16,055/ha treatment (474.8 g and 38.4 cm). Cost of producing a 142 g stocker was $0.409. For the economic analysis, phase 2 production area was based on producing sufficient stockers for all phase 3 ponds within a representative 445 ha operation. Enterprise budgets were developed for the 12,350/ha and 16,055/ha treatments and the incomes above variable cost and net returns to land were $1,450/ha and $399/ha and $108/ha and $944/ha, respectively. Low survival in phase 2 stocker production reduced returns. The three-phase modular system should provide additional management benefits not valued in this analysis.