If you made a Roth IRA contribution for 2016, it will be reported by your investment firm on IRS Form 5498, IRA Contributions Information, in Box 10.
If you made any 401k contributions during the year, the contributions would display on your Form W-2 in Box 12, with the Code D displayed (this is the IRS code designated for elective deferrals made to a 401k plan).
Please see the following TurboTax FAQ on "What Is IRS Form 5498: IRA Contributions Information?":
https://turbotax.intuit.com/tax-tools/tax-tips/IRS-Tax-Forms/What-Is-IRS-Form-5498--IRA-Contribution...
