No Net Loss of Private Lands Act - Authorizes the National Park Service, the U.S. Fish and Wildlife Service, the Bureau of Land Management, and the Forest Service to acquire an interest in 100 or more acres of land within a State only if, before acquisition, the agency: (1) disposes of the surface and subsurface estate to land in the United States, or in a U.S. territory, by way of transfer to a non-Federal party; and (2) certifies that the value of the land disposed of is equal to the interest of the land to be acquired.

Requires the head of such agency to dispose of the surface and subsurface estate to land in the same county as the land to be acquired, or if that is not feasible, in the same State.

Subjects acquisition of land within a State to this Act if 25 percent or more of the land within the State is federally-owned.

Excludes specified lands and properties from this Act.

Authorizes the head of an agency to waive such land acquisition requirements during a declaration of war or national emergency.