Madison and nearby school districts annually publicize their National Merit Scholar counts.
Consequently, I read with interest Madison School Board member Ed Hughes’ recent blog post:

We brag about how well Wisconsin students do on the ACT, and this is certainly good. But about 30 states have higher cut scores than Wisconsin when it comes to identifying National Merit Scholars, which means that their top 1% of students taking the test score higher than our top 1% do. (We in the MMSD are justly proud of our inordinate number of National Merit semi-finalists, but if – heaven forbid – MMSD were to be plopped down in the middle of Illinois, our number of semi-finalists would go down, perhaps significantly so. Illinois students need a higher score on the PSAT to be designated a National Merit semi-finalist than Wisconsin students do.)

I asked a few people who know about such things and received this response:

The critical cut score for identifying National Merit Semifinalist varies from state to state depending on the number of students who took the test and how well those students did on the test. In 2009, a score of 207 would put a student amongst the top 1% of test takers in Wisconsin and qualify them as a National Merit Semifinalist. However this score would not be high enough to qualify the student as a semifinalist in 36 other states or the District of Columbia.

View individual state cut scores, by year here. In 2010, Minnesota’s cut score was 215, Illinois’ 214, Iowa 209 and Michigan 209. Wisconsin’s was 207.