For ACS 5-year estimates that straddle 2010 (2007-2011 to 2009-2014), or all census tract estimates from the 2010 Census Tract boundaries? My guess would be that this would be the case starting with the 2006-2010 ACS estimates, but I just wanted to confirm.
The changes in New York State are all in Madison and Oneida counties (except combining some water tracts off Staten Island), AND they all happened in 2011, so I don't think you have to worry about changes…
I think you're asking: did ACS products make a product-wide switch to 2010 Tract boundaries in 2010? The answer is yes. Census Bureau ACSO retains the individual household-level responses collected thru ACS. The responses are geocoded to an X, Y point location. And those points can be identified with new tract memberships or new city memberships (if boundaries change) during the 5 years that those records are used in ACS "5-year" tabulations. That make sense?
There were some changes in 2011 and 2012 and then they stopped. They do not change boundaries between Censuses, and the CA change was an error correction. The 2020 blocks are way better than the 2010 blocks. There were no changes in NYC tracts after the 2010 Census, and the 2020 tracts are very similar to the 2010. They do change the political and administrative boundaries in between Census years, and do it more or less every December. The ACS generally lags about one year. There was a change in upstate NY.
Thanks, Andrew