Regional Jet 200 ER/LR (CRJ200)
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Distraction; Situational Awareness
Deviation - Altitude Undershoot; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter Wake Vortex Encounter
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Human Factors
During approach clearance; ATC cleared us for the ILS 4R; maintain 1;500 ft. until established; which I read back. We bugged 1;500 ft.; but we stayed at 2;000 ft. ATC called us about 60 seconds later and said we needed to descend to 1;500 ft.We were distracted by a wake turbulence encounter when cleared for the approach. Even though I read it back; in my mind I assumed it was at or above instead of the maintain clearance; so I didn't say anything to the First Officer who was the Pilot Flying.Make sure the clearance is fully understood; even if we need to query ATC.
CRJ Captain reported a wake vortex encounter that resulted in an altitude deviation.