The $18,000 contribution limit is for a Roth 401(k). If you are contributing to a Roth IRA the contribution limit is $5,500. Which type of account do you have?
Additionally, if your elective deferrals to the retirement account are shown on the W-2 box 12, then you do Not enter them again in the IRA contribution section of the program.
I am active duty military and contribute part of my paycheck to the government TSP (Thrift Savings Plan) traditional and Roth. The TSP site says my limits are $18k. They are indeed listed already in box 12 of my W2.
Enter amounts shown in box 12 of your W-2 only on TurboTax's W-2 form, nowhere else in TurboTax. Your TSP is not an IRA.
This also misled me, 401k's are entered on your W2 form which confused the program when I re-entered the contribution. Why don't they clarify/simplify this# and just put all plan information on the W2 form...
Personal traditional and Roth IRA contributions are not reported on a W-2 form because they are not employer plans. Since some individuals have income from self-employment, alimony and other sources which qualify as compensation for making an IRA contribution, personal IRA contributions must be handled separately from Forms W-2.
A TSP *is* an employer plan, not an IRA, so it is handled by entering on TurboTax's W-2 form, just like a 401(k).