<prompt> Human: I currently invest 5 base pay into my tradition TSP and 1000month into ROTH TSP. I have hit the point where I can make the 17.5k contribution to my TSP. If I have already filed taxes for the 2012 year, could I still go back and max out my TSP and also open and max out a ROTH IRA with Vanguard for the 2012 year?Also, currently I am putting everything into a target retirement fund with my TSP account. If I were to open a ROTH IRA, should I do the same with Vanguards target retirement fund?I dont really know why I am splitting 5 trad and 1000mo ROTH in my TSP, should I just convert this all to ROTH?  <response>: could I still go back and max out my TSPNo. You can only contribute through payroll deductions.open and max out a ROTH IRA with Vanguard for the 2012 year?Yes. Roth IRA contributions do not affect your taxes unless you qualify for the savers credit.should I do the same with Vanguards target retirement fund?You could, but allocations would probably be off due to the amount of funds you have in each. You could sort of compensate for this by choosing a TD fund that made the allocations work. Since I believe the expense ratios in the TSP are the same no matter what you choose, I would stick with that there. Then in your IRA, try to balance your allocation figuring in what your TSP allocation is.I dont really know why I am splitting 5 trad and 1000mo ROTH in my TSP, should I just convert this all to ROTH?This really depends on how you feel your tax situation will be in retirement. If you are in a high tax bracket now, it might be worth it to be doing all traditional. If you convert all your traditional to Roth, you will owe taxes on the converted amount. 