Let’s Encrypt will issue 64-day certificates by default on the classic ACME profile starting February 10, 2027, with 10-day authorization reuse. Staging switches October 14, 2026 for testing. Last 90-day certificates expire by May 11, 2027. Operators should renew at ~⅔ of lifetime (~day 43), verify ACME Renewal Information (ARI) support, and replace hardcoded renewal offsets (e.g., 83/80/60 days). Classic profile moves to 45-day certificates February 16, 2028 per earlier roadmap.