"Pickups" is a term commonly used in the world of assessing that refers to the annual inspection of those properties that have undergone some form of "new construction". This is the process by which an assessor visits any and all properties that have undergone renovations, additions, deletions or the completion of renovation or additions started in the previous year. This information is generally
received through inventories or building permits. 

The assessor is required to assess these changes as they existed on April 1st of each year and not after. In other words, if a property owner adds an addition or renovates their home after April 1st, it is not assessable until the following April 1st.