can you have a roth and a roth 401k
1 Higher contribution limits are permitted with a Roth Individual 401k than a Roth IRA regardless of income. 2  In 2015 participants can contribute up to $18,000 to a Roth 401k and $23,000 if age 50 or older. 3  The 2015 Roth IRA contribution limits are $5,500 and $6,500 if age 50 or older.owever, a Roth Individual 401k allows much higher annual contribution amounts than a Roth IRA. In 2015 a Roth IRA has a $5,500 limit and $6,500 limit if age 50 or older. The 2015 contribution limit for the Roth Individual 401k is $18,000 and $24,000 if age 50 or older.