(side note, been reading a lot of personal finance blogs in the past year or so every so often I am going to hit items like that in the future)
I am not a financial advisor so take this with a grain of salt, this is just my observations.
As a federal employee (times 2 actually, since I am federal civilian and a Army National Guard Officer) I get the opportunity to invest in the federal Thrift Savings Plan (TSP). On my civilian side it is a solid deal (considering that it is in addition to a defined benefits plan, FERS, that while nice isn't as nice as all the other other government employee programs (for some (good) reason state and local plans are the ones that really seem to create a lot of the controversy, because they were underfunded by their organizations and are insanely generous)).
Some basics. First off, for any federal civilian employee under FERS, if you are not contributing 5% of your salary, you are leaving money on the table (there is an automatic 1% contribution, but to get the full matching you really need to do 5%, which gets the other 4% matching fees into your account, where it can start doing some work for you.
Now the biggest complaint against TSP is the lack of fund selection, which is a fair complaint, since there are only 5 basic options (2 of which are effectively bond funds). Some of these complaints come from before 2001, since back then there were only 3 funds, the 2 bond funds and a general stock fund. But the 3 other options should give you a comprehensive risk exposure across a number of asset classes. They are:
- C Fund - Mirrors the S&P 500.
- S Fund - Mirrors the Dow Jones U.S. Completion Total Stock Market Index, a broad market index made up of stocks of U.S. companies not included in the S&P 500 Index.
- I Fund - Mirrors the MSCI EAFE (Europe, Australasia, Far East) Index.
- G Fund - The one controversial part of TSP and the frequent focus of legislation. If they ever change it to non-favorable terms (right now they get a weighted average of 4+ year returns of the Treasury notes, which means we are getting long term rates on a short term asset, which has attracted the attention of the Congress-critters) I know I will be engaged in a rebalancing in that event.
- F Fund - Matches Barclays Capital U.S. Aggregate Bond Index, which is more variable than the G Fund but often has a higher return. Less stable but more like regular bond funds.
There are also some "L" Funds that build a basket of the above items and are centered around when you expect to retire, basically slowly shaping your investments to be more conservative options the closer that date gets.
So overall, while solid it doesn't sound like the best deal (beyond of course putting in that minimal 5% to make sure you aren't leaving money behind). But the kicker comes when you look at fees. As of 2015 (https://www.tsp.gov/InvestmentFunds/FundsOverview/expenseRatio.html) the average expense ratio is .029%, which is the lowest among all my assets (and because just a little over 71% of my retirement assets, 55% of my total assets, it drags down my average to .05% in annual fees).
When I get a little older (maybe when I hit 50, 55) I may have to do some analysis of whether, from a tax perspective, it makes sense to explore the Roth TSP option.
BTW, one interesting feature. You can effectively make a loan to yourself (https://www.tsp.gov/PlanParticipation/LoansAndWithdrawals/loans/index.html) for up to $50,000. Other than a $50 cost, the interest rate you get is the effective rate of the G Fund. But the more interesting part is that any interest you pay is put into your account (so basically the marginal cost is keeping that amount loaned at a lower rate than it could earn in the other funds).