Yep, the max, 15.(15+1 chambered.)
All but 2 of mine, I would feel safe to carry with a round chambered. This is a practice my wife is not comfortable with. (So I don't, or I don't mention it to her.)
If the clip, (Or magazine, LOL.) WILL allow you to cram 1-more round, don't do it. One-time wouldn't hurt it, but leaving it that way might damage the spring.
If you do chamber a round, and do this with the same-round..(The first in the cli...EXCUSE ME, 'Magazine'...lol) That round can develop a setback. The projectile is pushed back minutuely from repeated-trips up the loading-ramp. This can cause foreshortening of the round and overcommpression of the powder.
A dangerous condition most would never think about.