{"data":{"id":"us/39-cfr-121.0","jurisdiction":"us","citation":"39 CFR 121.0","heading":"Market-dominant product service standards.","body":"Service standards in this part are contingent upon proper acceptance before the applicable day-zero Critical Entry Time (CET). Applying the service standards appearing in this part, effective service standards for combinations of 5-digit originating ZIP Codes and 5-digit destinating ZIP Codes can be found in a lookup table at www.usps.com.","path":["Title 39—Postal Service","CHAPTER I—UNITED STATES POSTAL SERVICE","SUBCHAPTER C—POST OFFICE SERVICES [DOMESTIC MAIL]","PART 121—SERVICE STANDARDS FOR MARKET-DOMINANT MAIL PRODUCTS"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-39.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:25:51Z","sha256":"c1114c32b0d01e9068c673bfd6d137cd2511ef655e3c8a68f95b2ab8174aa79a","source_id":"us-cfr","stale":true,"prev":"us/39-cfr-111.4-111.5","next":"us/39-cfr-121.1"},"notice":"GroundRules: Original legal text. Not legal advice."}