How do I prove my child did not live with me this year when receiving a county waiver program and claiming the w2 as income?

[creativecreation]

My child lived with me year 2017 and receiving a county waiver. I received a 2014-7 with my w2 and didn’t count income. This past year 2018 my child did not live with me as I did not receive a 2014-7 so I filed a normal w2. My parents also worked for my son but he lived with them, they did not claim the w2 as a 2014-7. How do I prove he lived with them and not me to help my taxes? (Assuming why it’s being held) 

[Vanessa]

Below is a list of ways the IRS accepts to prove he has an address that was not yours.

•  "you could send copies of school records for your child that have your name and show the child's address. The dates on the document must be for more than half the tax year (for school records you may need more than one semester to show more than half the year).
• If you moved and you and your child lived at another address, you must send documents showing the same address for both of you for more than half the tax year.
• If your child didn't go to school, you can send in copies of medical records or a statement from a daycare provider.
• If you need to get a statement from your child's school, daycare or medical care provider, you can find templates here. Your school or provider can copy and paste the template to their letterhead to make sure all the required information is provided."

https://www.irs.gov/taxtopics/tc654