What's with all the hate on the lifecycle funds? They're made up of the other funds and are balanced by a professional. Odds are very good unless you're carefully tracking the internals of each of the other funds that the allocation the lifecycle comes up with is going to be smarter than you are. I'd suggest that if you put in regular time and energy to researching, studying, and then re-balancing your portfolio, that's of course best...but if you're not committed to and educated on how to do that, the lifecycles were custom-made for you.
The TSP 2050 is something like 85% made up of the pure stock funds you all are advocating (https://www.tsp.gov/InvestmentFunds/FundOptions/fundPerformance_L2050.html) and it provides just a touch of ready-made diversification against market crashes. Diversification, within reason, is advocated in all of the books that are being touted above on this page in the thread.
If you're against it because you have a more aggressive mindset (more aggressive than 85% pure stock...), that's okay, but it's not the end of the world to use the things.
One other point...several of you have mentioned that there are mutual funds for use in Roth IRAs with 'similar' expense ratios to TSP...the C-fund (S&P 500 tracker fund) has an expense ratio of .042%. Vanguard's S&P 500 index fund expense ratio is .17%. For those of you following along at home, that means that while Vanguard is one of the least expensive commercial companies, they still charge you *4 times as much*. Their Admiral shares (which you can access after putting 10K or more into the fund, if I recall correctly) are a lot closer (.05%), but just keep in mind that the very best deal in the commercial sector struggles and still gets beaten out by TSP. The difference in real dollars isn't necessarily huge, but it's something to remember. Also remember that USAA and other non-Vanguard, non-TSP options are going to charge you even more.
