This bill, titled the Neighborhood Tree Act of 2026, amends the Cooperative Forestry Assistance Act of 1978 to establish a new Neighborhood Tree Fund . The fund's primary purpose is to provide financial assistance to eligible entities, including States, Indian Tribes, and various local government or community organizations, to increase and improve the overall health of the tree canopy within communities. The Secretary of Agriculture, in consultation with the Secretary of Housing and Urban Development, will establish requirements for receiving this assistance, which include community engagement, tree canopy assessments, and the use of climate change science in project design. Priority for assistance from the fund will be given to projects that focus on tree planting and maintenance in low-income census tracts , areas historically designated as "hazardous" or "definitely declining," or communities with lower tree canopy and higher daytime summer temperatures. Additional priority is extended to projects that optimize outcomes for climate mitigation and resilience for public health, or those that advance community-led urban agroforestry and tree-based local food production. The bill authorizes significant appropriations for the fund, starting with $100 million in fiscal year 2027 and increasing to $700 million by fiscal year 2031. Furthermore, the bill expands the National Urban and Community Forestry Advisory Council from 15 to 16 members, adding specific representation for residents of small communities and low-income communities.