Is 35 to old to join the army?

I won't lie, I'm surprised you had an age waiver approved, since anyone without prior service is supposed to have shipped to BCT prior to their 35th birthday, but congratulations nonetheless! 12B was actually my first MOS, though I was 18 when I went to 12B OSUT in 1998. We did have a 30 year old in my platoon during training, and he was able to keep up very well and was generally more squared away and composed than the rest of us. Your maturity and experience at 35 should actually be more of an asset to you during BCT than a hindrance. I think too many people harp on the physical aspect of military training and lifestyle, as if it were the be all end all. It does have an impact, but military training and lifestyle are far more mental than physical. Besides, 35 is the new 25!

If you are in good physical shape and you are sure that's what you want, go for it.

I enlisted at 34 and turned 35 at BCT. Got accepted into OCS at 36. If you are physically and mentally fit, your age won’t stop you from progressing.