Spain has a highly regulated planning system with a highly regulated and large set of N-NDOs. The implementation of urban plans must most of the time follow the land readjustment (LR) procedure, which includes the obligatory N-NDOs and the possibility of agreeing additional NDOs. However, it took several policy and legal reforms to improve the performance of LR. After LR legislation became a regional matter in the 1990s, different models appeared. The ‘Basque model’ supports on a public-private governance approach and the use of the expropriation tool. The ‘Valencian model’ supports on a novelty: to give municipalities the statutory powers to select a third party (not necessarily owning land) as implementer of LR and to apply compulsory LR with this third party as beneficiary. In general, since the 1980s, the actual delivery of N-NDOs and NDOs improved notably. NDOs have more or less constantly coexisted with N-NDOs, not jeopardizing them. There seems to be a trend to regulate NDOs and gradually transform them into N-NDOs.