B737 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Type 6269
Communication Breakdown; Confusion; Distraction; Situational Awareness
ATC Issue All Types; Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Clearance
Flight Crew Requested ATC Assistance / Clarification
Human Factors; Procedure
Center told us to descend VIA the MSCOT4 for 26R transition into IAH. Switching to approach they told us descend and maintain 12;000. After switching to another approach controller; he told us we were cleared for the 26L transition. We are now approaching MSCOT which has an altitude of 10;000 and I asked the controller if he still wanted us at 12;000. He said cleared for the 26L transition. After passing MSCOT the controller said we were supposed to be at 10;000. I said we were cleared for the 26L transition; but not to descend VIA. He then told us to descend to 7;000 and said; 'When I clear you for the transition that also means descend via'.
Air carrier Captain reported confusion with expected altitude on descent clearance from Houston Approach.