Last year the IRS announced that, effective May 1, 2000, a new program would allow it to update taxpayers’ addresses using the U.S. Postal Service’s national change of address (NCOA) database. Previously a taxpayer’s “last known address,” although not defined by statute or regulation, had been determined by case law to be the address that appeared on the taxpayer’s most recently filed and properly processed return. Furthermore, the IRS issued proposed regulations to reflect this new definition. But in announcement 2000–49, the IRS said it would delay the program’s start because it could not complete by May all the steps necessary to implement the regulations. The service did not give a new start date.