Medical device design controls are the documented steps that turn user needs into a verified, validated device design. Since February 2, 2026, FDA enforces them through the QMSR and ISO 13485:2016 clause 7.3 instead of 21 CFR 820.30. This guide maps the old paragraphs to the new clauses, explains verification versus validation and the ISO 14971 risk link, covers what investigators ask for under Compliance Program 7382.850, and uses Atlas data on 389 device Form 483s from 2026 to show which design clauses FDA cites most.