{"data":{"id":"us/26-cfr-1.66-5","jurisdiction":"us","citation":"26 CFR 1.66-5","heading":"-5 Effective date.","body":"Sections 1.66-1 through 1.66-4 are applicable on July 10, 2003. In addition, § 1.66-4 applies to any request for relief filed prior to July 10, 2003, for which the Internal Revenue Service has not issued a preliminary determination as of July 10, 2003.","path":["Title 26—Internal Revenue","CHAPTER I—INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY","SUBCHAPTER A—INCOME TAX","PART 1—INCOME TAXES"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-26.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:25:11Z","sha256":"cc3109e38690ee5a6b8aa154eb05462bfeabd5eaa98e4e5a8c1d5e9a322f5bef","source_id":"us-cfr","stale":true,"prev":"us/26-cfr-1.66-4","next":"us/26-cfr-1.67-1t"},"notice":"GroundRules: Original legal text. Not legal advice."}