In most of the USA the local telcos are obligated to extend service to new construction as part of government grants they've received in the past. The obligation is usually for something like ~10 years, but the grant cycle is shorter than that.
The recent "RDOF" mega-grant has one of these clauses (at the census block level):
"All support recipients must serve locations newly built after the revised location total but before the end of year eight upon reasonable request"
These mega-grant things happen every 6-8 years. The last was "CAP II", preceded by "CAP I", etc. The telcos are basically treated like municipalities when it comes to federal grantmaking. This is basically the system that was lobbied into place after AT&T was broken up; the FCC just took over AT&T's local-loop capital allocation.
The recent "RDOF" mega-grant has one of these clauses (at the census block level):
"All support recipients must serve locations newly built after the revised location total but before the end of year eight upon reasonable request"
https://www.fcc.gov/auction/904/factsheet
These mega-grant things happen every 6-8 years. The last was "CAP II", preceded by "CAP I", etc. The telcos are basically treated like municipalities when it comes to federal grantmaking. This is basically the system that was lobbied into place after AT&T was broken up; the FCC just took over AT&T's local-loop capital allocation.