Replaces everything after the enacting clause. Amends the Property Tax Code. Provides that, in a county with 3,000,000 or more inhabitants, for taxable years 2020 through 2024, a taxpayer who has been granted a senior citizens homestead exemption need not reapply (currently, the taxpayer must reapply annually). Provides that, if the property ceases to be qualified for that exemption in any year for which a reapplication is not required, then the owner of record of the property shall notify the chief county assessment officer that the property is no longer qualified. Provides that the chief county assessment officer shall enter into intergovernmental agreements with the county clerk of his or her county and the Department of Public Health, as well as any other appropriate governmental agency, to obtain information that documents the death of a taxpayer who has been granted a senior citizens homestead exemption. Makes conforming changes in provisions concerning erroneous homestead exemptions. Effective immediately.