One of the biggest mistakes anyone can make when applying to PA school is applying late. I made this mistake the first and second time applying. It doesn’t have to be a mistake if you do your research and apply strategically. Regardless, you should aim to submit your application as early as possible to increase your odds.
Not all programs are created equal, many programs have rolling admission, whereas others are deadline based. Rolling admission is where they review your application whenever it is submitted then score your application. There is no specific rule of thumb on when to avoid applying to a rolling admission program, so use your own judgement. Also note, many rolling admission programs have already offered majority of their seats prior to their specific deadline, therefore, it decreases the probability of an acceptance.
When applying late, find programs that do not use a rolling admission. A list of programs can be found here. For example, one program will not review applications until February 1st, thereafter they will score and extend offers for an interview. This gives the applicant plenty of time prepare their CASPA application. It’s advised to review their website and/or email to confirm they are still rolling admission before submitting. You don’t want to throw away money on an application, because it could be better used on different program application or a pumpkin spice latte.