Designer Program Series 4 is a subtheme of BrickLink introduced in 2025 and currently consists of 5 sets. All sets were released in 2025. As of today, the average annual growth of sets in BrickLink Designer Program Series 4 is approximately 21.3% but this should level out to around 12.8% in the coming years. This change in annual growth is primarily due to the initial retirement of these sets.
The BrickLink Designer Program Series 4 is a fan-driven initiative where LEGO enthusiasts submit custom designs for potential production as official LEGO sets. The program involves a voting process to select finalists, followed by a crowdfunding phase where supporters can pre-order their favorite designs. Sets that reach a minimum of 3,000 pre-orders will be produced, with a cap of 30,000 units per set. The five selected sets for Series 4 are Wild West Train, Siege Encampment, Merchant Boat, Medieval Seaside Market and Riverside Scholars. Pre-ordering started on Februrary 4th, 2025 with production and shipment in July 2025. Both the Medieval Seaside Market and Siege Encampment sold out the first day.