Hello,
I am looking for population counts by Census tract, grouped by ages (<1, 1y, 2,y, 3,y, 4y, and 5y). Is ACS data collected at this level or it is all grouped as "under 5"? Thank you!
You need to use PUMS data which has 1 year age intervals. You can try to use small area estimation to get numbers for census tracts.