Narrative:

We recently had a change in airspace and procedures with C90 climbing departures northbound to 15;000 (it used to be 13;000). I had an overflight that was at 16;000; he asked to descend to 12;000 as soon as he was clear of C90 airspace. There was aircraft departing ord that were also traffic for him. Once aircraft was clear of C90 and departing traffic; I descended him to 12;000 without thinking about the fact that I was over milwaukee approach airspace who owns up to 13;000. I was more concerned with missing the new C90 airspace. All the airspace below us was uniform when it was at 13;000. The change in procedures took my attention away from milwaukee approach airspace. Nothing happened from the incident other than I descended into somebody else's airspace with no appreq. I have worked this airspace very little since the change in airspace and procedures.

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Original NASA ASRS Text

Title: ZAU Controller descended aircraft into Milwaukee airspace after the traffic cleared the lateral confines of C90 airspace. Reporter cited confusion following a recent airspace change.

Narrative: We recently had a change in airspace and procedures with C90 climbing departures northbound to 15;000 (it used to be 13;000). I had an overflight that was at 16;000; he asked to descend to 12;000 as soon as he was clear of C90 airspace. There was aircraft departing ORD that were also traffic for him. Once aircraft was clear of C90 and departing traffic; I descended him to 12;000 without thinking about the fact that I was over Milwaukee Approach airspace who owns up to 13;000. I was more concerned with missing the new C90 airspace. All the airspace below us was uniform when it was at 13;000. The change in procedures took my attention away from Milwaukee Approach airspace. Nothing happened from the incident other than I descended into somebody else's airspace with no appreq. I have worked this airspace very little since the change in airspace and procedures.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.