I turned 50 in January, 2018. Can I contribute $6500 to my Roth IRA?

[JohnW15]

The maximum amount you can contribute in 2018 is $6,500; in 2017, that amount would've been $5,500 for you, since you weren't yet 50 years old. 

However, your adjusted gross income may affect the amount you can contribute.  Please see the IRS’ Amount of Roth IRA Contributions That You Can Make For 2017.  

[SweetieJean]

2018, not 2017.

[SweetieJean]

<a rel="nofollow" target="_blank" href="https://www.fool.com/retirement/iras/2017/10/23/2018-roth-ira-income-limits-what-you-need-to-know.as...>

[dmertz]

More clearly, the maximum that you can contribute *for* 2017 is $5,500, even if the contribution for 2017 is made in 2018.