How to write off payment to previous employer

[superbean2008]

Just started a new job and got sign-on bonus aiming to pay back my previous employer for the cost of green card fee (in 2019, not on W2), education assistance (in 2020, qualified edu assist program, not on W2) and sign-on bonus (in 2019, on W2). Can these be treated as cost of my current job and deducted from current sign-on bonus in tax return?

[RobertB4444]

Probably not.

Employee business expenses were removed as a deduction in 2018.  If you are a contractor, then you can remove these expenses as expenses for your business.  If you are an employee, then these expenses are deductible on a few state tax returns but not on your federal return.

Here's the IRS guidance on employee business expenses.