You are billed monthly for the duration of the plan you select.
If you purchase the 6 month payment plan for Stages 1& 2, or the 6 month payment plan for Stage 3, your second shipment will ship the remaining product upfront. After the second shipment, you will not receive any more orders, and the next 4 months will be payments for the upfront shipping only.
If you purchase the complete system 6 month payment plan, you will receive your orders in 4 shipments. The first two months will ship Stages 1 & 2 upfront. Month 3 will be a payment only for the bulk order of Stage 2. Month 4 will ship 1 Stage 3 order, and month 5 will ship the remaining Stage 3 orders upfront. Months 6 will be a payment only for the bulk order of Stage 3.
If you have purchased the complete system 12 month payment plan you will receive orders in 4 shipments. The first two months will ship Stages 1 & 2 upfront. Months 3-6 will be payments only for the bulk order of Stage 2. Month 7 will ship 1 Stage 3 order, and month 8 will ship the remaining Stage 3 orders upfront. Months 9-12 will be payments only for the bulk order of Stage 3.