Page 10 of the instructions for the W-2 Form outline what should be included in box 10 of the W-2. It states, show the total dependent care benefits under a dependent care assistance program (section 129) paid or incurred by you for your employee. Include the fair market value (FMV) of employer provided or employer-sponsored daycare facilities and amounts paid or incurred for dependent care assistance in a section 125 (cafeteria) plan. Report all amounts paid or incurred (regardless of any employee forfeitures), including those in excess of the $5,000 exclusion…….
The instructions may be found at:
http://www.irs.gov/pub/irs-pdf/iw2w3.pdf