I got my national merit semifinalist letter, but I am curious if my chances are completely ruined. My freshman year I came to a new school with a tougher grading scale than I was used to (93-100 A, 85-92 B, etc.) and ended up getting Cs both semesters. The teacher was very tough and was not much help when I went in for extra assistance. I am wondering if National Merit takes into consideration the grading scale because all 3 Cs would have been Bs at any public school. I’m yelling at my freshman year self right now. PS I have good extracurriculars and a 35 on the ACT but only a 3.5 UW GPA. I know my chances are probably terrible but I would love any input because these scholarships are my best chance at getting out of the state for school.
Also should I address my poor grades in my essay or try to highlight other aspects of my life?
I would not address the grades in your essay. Keep the essay positive.
Most students are at a new school (high school) for 9th grade - this is not unique, nor is it unique that some students have a period of adjustment to the new rigors of HS. I don’t know the NM policy, but I would think that freshman-year grades might not carry the weight of later grades and involvement. All you can do is submit the app and see what happens.
Your school has to submit a recommendation with your NMF application. Perhaps you could ask your GC to address it briefly. You could say that you are concerned about your C’s, and ask if he would be willing to include something regarding your marked improvement during 10 & 11th grade. He may even be able to reassure you if he has experience with similar applications in the past.
^^Good advice. @lydtraut one of the ways they weed out the kids who don’t advance is via poor grades on the transcript, from everything I’ve been reading in these forums. However, it might depend on which subject you got those C’s? Not sure. Obviously a college admissions committee looks at honors math a bit differently from gym. But NMSC seems to look at overall GPA and the the pattern of student/academic progress.
If your GPA were around a 3.0 or lower I’d say it’s not likely simply because I know of similar circumstances (schools were rigorous as well). But given the small number and the timing of those C’s, you should definitely go for it and see what happens. If your school is exceptionally rigorous then NMSC will see that in the counselor report or from the school’s history of other nmsf’s and take that into account.
Regardless of the outcome, you already met the highest hurdle which is to become a semifinalist in the first place - a major accomplishment! And that 35 certainly won’t hurt when you begin applying to colleges 
Hi I was a semi finalist last year and was in a similar situation. I did address the Cs I had in my essay but I did not end up moving on to finalist. Read the NMF thread for the class of 2016 to follow my journey in detail.