If they aren't, then you might do better to set up an IRA through a bank or financial planner to get higher yields, and have greater flexibility with the money (with a Roth IRA, you can use the money towards educational expenses and/or for a downpayment on a house with far less penalties than in a traditional IRA). If they *are* matching (or at least contributing something) then stick with the 401k, 'cuz the contribution amounts to free money!

Oh, and, welcome to adulthood :-)