For NYC public schools, there is also testing on a separate schedule for 2-3.
For a third grader who will be going to 4th, or a 4th grader going to fifth, admission to G&T is NOT guaranteed and kids are on a list with ranking based on their performance on the NCLB exam, which is a proficiency exam and not really good for determining giftedness. Kids from the list get spots in the G&T programs based on attrition.
Also, the test for K-3 is the group-administered OLSAT, which does a poor job of measuring "g." Per Hoagies, OLSAT scores do not correlate well to IQ test scores.
I'm disheartened that even if my younger child scores well enough on the OLSAT to get into one of these citywide schools, the schools themselves won't have as many HG or PG kids as they had in years past.
The admissions process is ridiculous. On the bright side, NYC is FINALLY opening some city-wide gifted schools outside of Manhattan: Long Island City, Queens; Clinton Hill, Brooklyn; and Bensonhurst, Brooklyn. One of them, the Brooklyn School for Inquiry
http://schools.nyc.gov/NR/rdonlyres/EC3DB525-69DB-4526-975B-888552CAEBDA/55188/KD21.pdf seems interesting. I think the new principal has spent some time at Anderson, one of the current city-wide gifted schools.
I'm guessing the other new city-wide G&T in Brooklyn will not be so great. It is being put in a school that is partially empty because so few local parents want to send their kids there, with a principal who is criticized for not wanting parent involvement, and that principal will also run the new program.
You can find out more about a LOT of NYC schools at
www.insideschools.org, which is run by the non-profit Advocates for Children.