Box 10 of your W-2 shows the total amount of dependent care benefits that your employer paid to you or incurred on your behalf. Amounts over $5,000 ($2,500 in the case of a separate return filed by a married individual) are also included in box 1.
You must complete Part III of Form 2441, Child and Dependent Care Expenses to figure the amount if any, that you can exclude from your income.
The link below has information that you may find useful.
https://www.irs.gov/faqs/interest-dividends-other-types-of-income/employee-reimbursements-form-w-2-w...