I recieved the following from VT:
"Important NGS News
NGS has recently announced a reprocessing campaign to update the coordinates of CORS stations across the country. This campaign, called the Multi-Year CORS Solution 2 (MYCS2) is aligned to the International Terrestrial Reference Frame (ITRF2014). NGS has also released the new geoid model GEOID18, intended to be the last hybrid geoid model that NGS creates before the current vertical datums are replaced by NAPGD2022.
These updates have potential impacts to the Vermont CORS Network users!
VTrans will be updating/confirming the coordinates of all 18 stations as soon as possible, but we ask that until we announce that stations have been reprocessed with new coordinates, that users DO NOT use GEOID18 in their data collectors to avoid data discrepancy.
We will be keeping users updated with this process and any impacts it may have on the Network."