Under the Wisconsin Constitution, the Governor may approve appropriation bills “in whole or in part.” The partial veto power afforded Wisconsin’s governors is considered to be one of the most extensive in the nation. Since its creation by constitutional amendment in 1930, Wisconsin governors have exercised the partial veto with increasing regularity and imagination. In response, the Legislature has challenged the Governor’s use of the partial veto in court and, on two occasions, amended the constitution with voter approval. This information memorandum provides background information on the authority of the Governor to partially veto appropriation bills under Wis. Const. art. V, s. 10 (1) and describes the limits on the Governor’s use of this authority.