The U.S. FDA’s draft rule for regulation of lab-developed tests (LDTs) carries an exceptionally ambitious timeline of completion and enactment by the time the next user fee agreement kicks in, and some see big problems with the timeline laid out by the agency. However, the FDA’s Elizabeth Hillebrenner said that Congress can tweak user fee legislation such that a specific set of user fee sources kicks in off schedule, thus giving the agency a little more leeway in completing any activity related to the proposed rule.