Updated: August 29, 2026
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If you have money in the Thrift Savings Plan, you already own a Lifecycle Fund by default or you have seen the option on your dashboard. The L Funds run on a specific set of rules, and those rules control how your money moves as your target date gets closer.
This page walks through the current lineup, the five funds sitting under every L Fund, the quarterly rebalance, and what happens the year your target date arrives. It focuses on the mechanics of how each L Fund actually works, not on which one you should pick.
The current L Fund lineup
The TSP offers eleven Lifecycle Funds. Ten carry a target year, and one carries no year at all.
The dated funds run in five-year steps. Right now the lineup covers L 2030, L 2035, L 2040, L 2045, L 2050, L 2055, L 2060, L 2065, L 2070, and L 2075. The most recent addition was built for participants who expect to reach age 62 in the mid-2070s and want to keep the same L Fund from the start of their career.
The eleventh fund is L Income. It does not roll forward. It is designed for participants already drawing from the plan or planning to start within a few years.
You pick the fund whose year matches when you expect to start pulling money out, not when you plan to stop working. Those two dates can be several years apart for federal employees who plan a delayed drawdown.
The five core funds behind every L Fund
Each Lifecycle Fund is a mix of the five individual TSP funds. Nothing more, nothing exotic.
The G Fund holds Government Securities. It is the only TSP fund with a share price that does not fall on a daily basis, and its holdings are Treasury securities issued only to the TSP. The F Fund tracks a broad Fixed Income index of U.S. bonds and can gain or lose value as interest rates move.
The C Fund tracks the S&P 500, so it holds the largest U.S. companies. The S Fund tracks a small and mid-cap index covering U.S. stocks not included in the C Fund. The I Fund tracks international developed and emerging market stocks.
When you buy an L Fund, you own slivers of all five in fixed target percentages. Those percentages are the only thing that changes over time. The individual funds themselves stay put.
The glide path and the quarterly rebalance
The core mechanic is called a glide path. Far from the target year, the L Fund holds more C, S, and I (stock exposure). As the target year gets closer, the mix shifts toward G and F.
Two separate mechanisms run this shift.
First, the target allocation itself moves every quarter. Every three months, the TSP moves the target percentages of each dated L Fund one step closer to the L Income endpoint. This is the glide path.
Second, the actual fund holdings are rebalanced back to the target at the end of every trading day. If stocks rally on a Tuesday and your fund drifts above target, the Tuesday close pulls it back. If bonds fall on Wednesday, the Wednesday close buys them back to weight.
Between quarterly target shifts, the daily rebalance is invisible to you. Between years, the target itself has drifted. Both mechanisms combine to move you along the glide path without you touching anything.
The L Income Fund does not shift quarterly. Its target mix is deliberately stable, because it is built for participants already spending down. The graphic below shows the same lifecycle applied to a single dated fund.
How the L Funds are priced day to day
Every TSP fund, including the L Funds, is priced once per business day. That price is called a share price, and it appears on TSP.gov after markets close.
An L Fund’s share price is a weighted blend of the five core fund prices, using the L Fund’s current target allocation. For example, if the C Fund gained 1% on a given day and the F Fund lost 0.5%, the L 2050 share price would move in proportion. The direction and size depend on how much C and F sit in the fund’s current mix.
This matters because contributions and withdrawals settle at the day’s share price. A payroll contribution that clears on Tuesday buys L Fund shares at Tuesday’s closing price. A withdrawal request that processes on Wednesday sells shares at Wednesday’s closing price.
There is no intraday trading of L Fund shares. The daily-close pricing is the same rule that applies to the individual funds.
What happens at the target year
The year printed on your L Fund is the year it disappears as a separate fund.
When a dated L Fund reaches its target year, the TSP merges it into L Income. L 2030 will merge into L Income in July 2030. L 2035 will merge in July 2035, and so on down the line.
You do not have to do anything on merger day. Your balance is not sold, and no tax event is triggered. Your L 2030 shares are converted into L Income shares at the same dollar value, and your allocation now follows the L Income rules.
If you want a different mix after that, you have to actively change your election. Nothing rolls into a new dated fund on your behalf.
L Income and the 2028 transition
L Income is the endpoint for every dated L Fund. It is also where the TSP is currently running a slow change.
The plan is transitioning L Income to a new target allocation. The transition is on schedule to complete in 2028. During the transition, L Income participants see the fund’s target mix drift each quarter toward the new endpoint.
If you are already in L Income, you keep receiving quarterly updates through TSP.gov. The fund does not stop moving during the transition, and the daily rebalance still runs.
L Income is built for people who need the money soon, so its stock allocation stays low. It is not a cash fund, and it is not principal-guaranteed. The G Fund slice inside L Income is what carries the daily stability.
The G Fund is the piece you cannot recreate outside TSP
The G Fund is one reason many federal employees keep money in the TSP after separation instead of rolling to an outside IRA.
By law, the G Fund is invested only in nonmarketable U.S. Treasury securities specially issued to the TSP. Nonmarketable means these securities are not traded on any exchange. You cannot buy them at a brokerage, and no ETF can hold them.
The G Fund’s interest rate is set monthly using a formula tied to long-term Treasury yields. The daily share price does not fall the way a bond fund’s price falls when rates rise.
Every L Fund holds a slice of G. As your target date gets closer, that slice gets larger. If you roll your TSP balance out of the plan into an outside vehicle, you leave that slice behind.
Auto-enrollment and the default L Fund
Since 2010, federal employees hired into a covered position are automatically enrolled in the TSP. The default fund is not one of the individual funds. It is a Lifecycle Fund whose target year is set based on the participant’s age.
A newly hired employee in their late 20s is enrolled into a fund with a target year decades out, so the initial allocation sits heavily in C, S, and I. A late-career hire is enrolled into a nearer-dated L Fund with a heavier G and F weight.
Nothing in the plan rules prevents the participant from moving out of the default. A future election can send contributions across any of the five individual funds, or across a different L Fund at any time.
The expense layer that applies to L Funds
L Funds carry no separate management-fee layer stacked on top of the core funds. There is no “fund of funds” markup.
Each L Fund pays only the same TSP administrative expenses that apply to G, F, C, S, and I. The exact expense ratio for every L Fund is disclosed on its dedicated page at TSP.gov and stated as basis points, typically in the low single digits. When the TSP publishes a new expense ratio each year, it applies uniformly to the L Funds and to the individual funds sitting under them.
The result: an L Fund investor pays the underlying TSP fund expenses in proportion to the L Fund’s target allocation, and no additional Lifecycle wrapper fee.
Why L Funds cannot be reproduced outside the TSP
An L Fund holds the five TSP core funds inside a single share price. Four of those funds (F, C, S, I) track public indexes that any commercial broker can replicate approximately with public index funds. One of them cannot.
The G Fund holds nonmarketable Treasury securities issued only to the TSP under 5 U.S.C. 8438. No IRA, no brokerage, and no ETF has access to that security type. TSP booklet TSPBK12 confirms the G Fund composition and the special-issue Treasury structure.
So an outside vehicle can approximate the F, C, S, and I sleeves of any L Fund but cannot copy the G sleeve. As the target year approaches and the G slice grows, the gap between what the TSP holds and what an outside portfolio can hold widens by design.
Where L Funds sit inside the broader rollover picture
After separation, a TSP participant has several documented options: leave the balance in the TSP, take a full or partial distribution, roll to another employer plan that accepts rollovers, or roll to an IRA. The L Fund allocation follows the balance only if the balance stays inside the TSP.
Once a balance moves out of the plan, L Fund mechanics no longer apply, and the quarterly rebalance stops running on that money. The receiving vehicle sets its own rules.
Rollover destinations range from another 401(k) or 403(b) plan, to a traditional or Roth IRA at a brokerage, to a self-directed IRA. A self-directed IRA holding IRS-approved physical bullion is one documented destination, permitted under IRC 408(m)(3) when the metal meets purity thresholds and is held by an approved custodian.
Documented mechanics, not a recommendation
Everything above describes how L Funds are built, priced, rebalanced, and eventually merged. None of it is a statement that any participant should hold an L Fund, switch to one, or roll a balance anywhere.
The TSP publishes the current lineup, the target allocations, and the expense ratios at TSP.gov. Those pages update as the plan changes. Any participant reviewing an L Fund choice should read the fund’s own page live before acting, because the allocation percentages and the L Income transition schedule can shift under a documented plan process.