This bill requires the U.S. Postal Service to provide curbside mail delivery to residents in certain housing developments and prohibits the agency from using its funds to eliminate or reduce this service. The requirement applies to housing developments defined as clusters of 50 or fewer single-family homes in subdivisions or neighborhoods that are located within 300 yards of other residences already receiving curbside delivery. The bill affects both the Postal Service and residents of qualifying residential areas by ensuring they maintain access to curbside mail service rather than alternative delivery methods. The legislation does not specify any new funding allocations or implementation timeline, instead directing the Postal Service to use existing funds, including those in the Postal Service Fund, to comply with the requirement.