I keep seeing posts about people choosing to use all their PTO and quit immediately after. Well I hate to be that person but it's to protect you financially.
You can legally be required to pay back any portion of your PTO that you have not fully accrued which likely will be some portion of it.
How does PTO work exactly? Each company might do it slightly different but typically you've given all your PTO at the beginning of the fiscal year but this isn't just given you to, you have to accrue it over the course of the fiscal year. Your PTO is essentially prorated to you on the agreement you work the full fiscal year.
Lets say your company gives you 4 weeks of PTO on January 1, each week you work you accrue ~3 hours worth of PTO, and over the course of the year it will accrue to 160 hours. Now lets say you quit within the first few months but not before you used all 4 weeks of PTO. Guess what, whatever PTO was not accrued for, you will have to pay it back or have it deducted from your final pay. Lets assume it was 75%, that will be 120 hours worth of your pay that you have to return to the company. Hope you didn't spend it.
TL;DR: Yes, you can be forced to pay back whatever PTO you did not fully accrue. Yes it's legal unless your state has laws that prevent this, most states do not.