My employer reimburses a part of my gym membership via Expensify, and it's not included on W-2. Should I report it as taxable income separately?

They are going to start including this benefit in W-2 starting 2020, but in 2019 I'm on my own and not sure if I need to pull all these reimbursements and report them. If I do, which IRS form/TurboTax flow do I follow?