Joint Plans outline land-use and development policies in the urban growth areas (UGAs) of Lacey, Olympia, Rainier, Tenino, Tumwater, and Yelm. Urban growth areas are unincorporated parts of the county that may be annexed by a city in the future. The joint plan is made with Thurston County and city governments working together. This leads to regulations that make future development more predictable for residents who live in those areas, and smoother when annexation occurs. Joint plans are part of the county's Comprehensive Plan and are updated regularly.

Joint Plans are not just documents; they result from a collaborative effort involving community members, city governments, and the county government. This process is designed to ensure that everyone's voice is heard and valued, with multiple opportunities for community input. These plans are reviewed by the City Planning Commission, the Thurston County Planning Commission, the City Council, and the Board of County Commissioners. The final adoption comes from Thurston's Board of County Commissioners, which adopts Joint Plans as part of the Thurston County Comprehensive Plan. 

Subarea plans are a subset of the Comprehensive Plan and provide a vision for growth and investment in a specific area 20 years into the future. Thurston County has three subareas: Grand Mound, Rochester, and Nisqually. These subareas can lead to regulations that make future development more predictable for residents in those areas. 

Subarea Plans are developed in collaboration with community members and the county government. The process includes multiple opportunities for community input. They are reviewed by the community stakeholders, the Thurston County Planning Commission, and the Board of County Commissioners. The final adoption comes from Thurston's Board of County Commissioners, which adopts Subarea Plans as part of the Thurston County Comprehensive Plan.