Census Data API: FIPS Geographies in /data/2018/pep/population/geography

Reference Date	Geography Level	Geography Hierarchy	Limit
14 items
2018-01-01	01	us
2018-01-01	02	region
2018-01-01	03	division
2018-01-01	04	state
2018-01-01	050	state› county
2018-01-01	061	state› county› county subdivision
2018-01-01	071	state› county› county subdivision› place
2018-01-01	157	state› county› place
2018-01-01	162	state› place
2018-01-01	170	state› consolidated city
2018-01-01	172	state› consolidated city› place
2018-01-01	310	metropolitan statistical area/micropolitan statistical area
2018-01-01	314	metropolitan statistical area/micropolitan statistical area› metropolitan division
2018-01-01	330	combined statistical area