If I contributed to a Roth 401(k), are those deductible?

[ChristinaS]

No, Roth contributions are never deductible.

When you contribute to a Roth 401(k) or Roth IRA, you are making a nondeductible, after-tax contribution.

When you take the money out when you get older, qualified distributions are tax-free. You get the benefit when you take the money out, not when you put the money in.