Using your TSP to bridge to Social Security at 70

1. The bridge, in one paragraph

You retire. You do not claim Social Security yet. For the years between retirement and your chosen claiming age, most often 70, you draw the money you would have received from Social Security out of your TSP instead. At 70 you flip: Social Security starts at its maximum, and your TSP withdrawals drop back to whatever your plan calls for. You have traded a slice of a finite, market-exposed, fully taxable account for a permanent increase in a guaranteed, inflation-indexed, partially taxable income stream that also protects your spouse. That is the entire strategy. The rest of this guide is about whether the trade is worth it for you and how to execute it without getting hurt.

2. What waiting actually buys

Your full retirement age is 67 if you were born in 1960 or later; the last cohort with a lower FRA reached it in 2026, so for nearly everyone still deciding, 67 is the number. Claiming earlier than FRA reduces your benefit by 5/9 of one percent for each of the first 36 months and 5/12 of one percent for each month beyond that; claiming later adds 2/3 of one percent per month, up to age 70. Nothing is gained by waiting past 70.

Three properties of that larger check are easy to underrate:

• It is indexed. Every Social Security COLA applies to the larger base. On the 2026 COLA of 2.8%, the age-70 check grows by $83 a month; the age-62 check grows by $47. The gap widens every year.
• It is guaranteed for life. A TSP balance can be spent down, mismanaged, or hit by a bad decade. The Social Security check cannot run out.
• It becomes your spouse’s survivor benefit. When the higher earner dies, the surviving spouse steps up to the higher earner’s benefit. Delaying raises the check your spouse may live on for decades. Section 8 covers this in detail.

3. Why federal retirees are unusually well placed

Most bridge-strategy writing is aimed at private-sector retirees who have nothing but a 401(k) between retirement and Social Security. Federal retirees are in a different position, and it makes the bridge both cheaper and safer.

The pension is the floor. A FERS annuity arrives every month regardless of what the market does. Social Security is therefore a smaller share of your total retirement income than it is for most Americans, and the bridge withdrawals are a smaller share of your TSP.

The supplement covers you to 62. If you retired on an immediate, unreduced annuity (MRA with 30 years, 60 with 20, or under VERA once you reach MRA), the FERS Special Retirement Supplement pays roughly what Social Security would pay you at 62, scaled by your years of FERS service, until the month you turn 62. So the TSP does not have to bridge from your retirement date; it only has to bridge from 62 to your claiming age. A 57-year-old retiring with 30 years and planning to claim at 70 has a five-year supplement and an eight-year TSP bridge, not a thirteen-year TSP bridge.

The TSP is built for this. The G Fund is the cleanest short-horizon holding available to any retiree in America: it pays a long-term Treasury rate with no principal risk. Installment payments can be set monthly, quarterly, or annually and changed at any time. And if you separated in or after the year you turned 55, the Rule of 55 means those installments carry no early-withdrawal penalty.

4. Run your own bridge

Enter your full-retirement-age benefit from your Social Security statement, the age you would otherwise claim, your TSP balance, and the return you expect on the TSP. The tool computes the check at each age, what the bridge draws from the TSP, what that money would have grown to if left alone, and the age at which the larger check has paid the TSP back.

5. What the bridge costs your TSP

Take the default case in the tool: a $2,400 FRA benefit, a $500,000 TSP, and a choice between claiming at 62 or bridging to 70. The 62 check is $1,680 a month; the 70 check is $2,976. To bridge, you draw $20,160 a year from the TSP for eight years, $161,280 in total. That is the visible cost.

The real cost is larger, because that money would have kept growing. At a 5% return, an untouched $500,000 grows to about $738,700 by age 70. The bridged account, after eight years of draws and growth on what remained, is about $536,600. The bridge therefore costs roughly $202,000 of TSP at age 70. In exchange you receive an extra $1,296 a month, $15,552 a year, for life. Straight division says the larger check has repaid that $202,000 about 13 years after 70, at roughly age 83.

That number deserves a plain reading. Age 83 is close to the median life expectancy of a 65-year-old today: SSA’s period life table puts it around 82 for men and 85 for women. On pure dollars, for one person, the bridge is close to a coin flip. Three things move it decisively in your favor, and none of them is in the straight-division figure:

• COLA. The $15,552-a-year advantage grows with every adjustment. At a 2.5% average COLA it is about $20,000 a year by 80 and $25,000 by 90. The break-even pulls back into the low 80s.
• Tax. TSP withdrawals are 100% taxable as ordinary income. At most 85% of Social Security is taxable, and many federal retirees are below the threshold where the full 85% applies. A dollar of Social Security is worth more after tax than a dollar of TSP.
• The survivor benefit. If you are married, the relevant life expectancy is not yours; it is the second-to-die. For a couple both aged 65, there is a better-than-even chance one of you reaches 90. Section 8.

Partial bridges: 67 or 68 instead of 70

The bridge is not all-or-nothing. Every month of delay earns the same credit, so a retiree who cannot comfortably fund eight years can fund three or five and still capture most of the benefit. Using the same $2,400 FRA case and a 5% return: bridging from 65 to 70 draws $2,080 a month for five years, costs about $145,000 of TSP at 70, and adds $10,752 a year for life, with a break-even around 83½. Bridging from 62 to 67, claiming at FRA, draws $1,680 for five years and lifts the check from $1,680 to $2,400: a 43% increase for a smaller TSP commitment than the full run to 70. The marginal value of each additional year is roughly constant, so the right stopping point is the one your TSP can fund with margin. Section 9 gives a rule of thumb for that margin.

One more framing that many retirees find clarifying. The bridge is the cheapest inflation-indexed lifetime annuity you can buy. A commercial single-premium immediate annuity that paid $15,552 a year, indexed to CPI, with a 100% survivor benefit, would cost a 70-year-old well over $300,000 in the 2026 rate environment. The bridge delivers the same stream for about $200,000 of TSP. Seen that way, the decision is less “will I live past 83” and more “do I want to own longevity insurance at a 35% discount.”

6. Building a bridge a bad market can’t break

The failure mode of every bridge strategy is the same: the market falls 30% in year two, you are forced to sell stock funds at the bottom to make the bridge payment, and the plan that looked fine on paper hands you permanent damage. This is sequence-of-returns risk, and the TSP gives you an unusually clean way to neutralize it.

Segregate the bridge money in the G Fund

Before the bridge starts, move the total you will draw during the bridge into the G Fund. For the default case that is eight years of $20,160, about $161,000. The G Fund cannot lose principal and pays a rate tied to long-term Treasuries; in 2026 that has run above 4%. The rest of your TSP stays invested in the C, S, I, or L Funds for the money you will not touch until after 70. A market crash during the bridge then has no effect on the bridge payments at all. You are never a forced seller.

Because the TSP takes installment payments pro rata across your funds unless you tell it otherwise, the practical step is an interfund transfer that sizes the G Fund to the bridge, then installments that come out proportionally. As the G share is drawn down, rebalance annually so the remaining bridge years stay in G. Some retirees prefer the simpler bucket approach, holding one to two years of bridge payments in G and topping it up from the stock funds in good years only.

Use installments, not a lump sum

Do not take the bridge money out of the TSP in one withdrawal. A lump sum is taxed in a single year, at your highest marginal rate, and it moves money from a 0.04%-expense-ratio plan into a bank account. Monthly installments keep the money invested, spread the tax across the bridge years, and can be changed or stopped online at any time. Set the installment to the monthly Social Security check you are replacing, and revisit it each January.

Mind the penalty rules

If you separated in or after the year you turned 55, the Rule of 55 exempts your TSP withdrawals from the 10% early-withdrawal penalty even before 59½. Special-category employees get the same treatment at 50 or with 25 years. If you retired earlier than that, the bridge cannot start from the TSP without penalty until 59½, and a rollover to an IRA destroys the Rule of 55 exemption entirely. Confirm which applies before you set the plan.

7. The tax window the bridge opens

The years between retirement and claiming Social Security are usually the lowest-income years of your adult life. A FERS pension is often your only taxable income, the supplement (if you have it) is small, and Social Security is at zero. That is exactly the window in which Roth conversions are cheapest, and the bridge deliberately extends it.

Consider a retiree with a $36,000 FERS pension and no other taxable income. The 2026 standard deduction for a single filer over 65, including the additional senior amount, is roughly $18,000 before the temporary $6,000 senior deduction that applies from 2025 through 2028. That retiree can convert tens of thousands of dollars of traditional TSP to Roth each bridge year and never leave the 12% bracket. Once Social Security starts at 70, the same conversion would be taxed at 22% or higher and would push more of the Social Security check into the taxable range.

The bridge and the conversion compete for the same low-bracket room, so plan them together. A common sequence: draw the bridge payments from traditional TSP (they are taxable, so they use bracket room), then fill the remainder of the 12% bracket with an in-plan Roth conversion. By 70 you have a larger Social Security check, a smaller traditional balance facing RMDs at 73 or 75, and a Roth TSP that is exempt from RMDs for life.

8. Couples: the survivor benefit changes everything

For a married couple, the bridge decision is not about one lifetime. When one spouse dies, the survivor receives the larger of the two benefits and loses the smaller. If the higher earner delayed to 70, the survivor keeps the age-70 check for the rest of his or her life. If the higher earner claimed at 62, the survivor is locked into the reduced check.

The arithmetic is stark. Using the $2,400 FRA example: if the higher earner claims at 62 and dies at 80, the surviving spouse collects $1,680 a month (plus COLAs) for however long she lives. If the higher earner had bridged to 70, she collects $2,976. Over a fifteen-year widowhood that is roughly $233,000 in today’s dollars, before COLA. That single number is why, for most federal couples, the higher earner bridges to 70 even when the lower earner claims early.

The usual couples pattern, covered in depth in the couples claiming strategy guide:

• Higher earner: bridge to 70 using the TSP. This sets the survivor benefit.
• Lower earner: claim at 62 to FRA, providing early cash flow and reducing the TSP draw. The lower earner’s own benefit will be replaced by the survivor benefit eventually, so delaying it buys less.
• Both pensions and both TSPs are pooled for the bridge; a two-federal-employee household often needs almost no TSP draw at all.

A worked federal couple

He is 61, retiring at 62 with 30 years: a $38,000 FERS pension and a $2,600 FRA benefit. She is 60, a GS-9 retiring at 62 with 25 years: a $22,000 pension and a $1,500 FRA benefit. Combined TSP: $700,000. Combined spending target: $110,000 a year. Pensions cover $60,000, leaving $50,000 a year to find.

The plan: she claims at 62 for $1,050 a month ($12,600 a year). He bridges to 70. The TSP must therefore supply $37,400 a year for eight years, about $300,000 of the $700,000, leaving roughly $400,000 invested. At 70 his check is $3,224 a month ($38,700 a year). Household income at 70: $60,000 in pensions plus $51,300 in Social Security, $111,300 before any TSP draw at all. The TSP, still around $660,000 at 5% because growth on the untouched $400,000 offset most of the draws, is free for discretionary spending, long-term care reserve, and heirs.

The survivor test is where the plan proves itself. If he dies at 78, she keeps his $3,224 check (plus eight years of COLA) and loses her own $1,050; she also keeps her pension and whatever portion of his pension the survivor election preserved. Had he claimed at 62 for $1,820, her survivor check would be $1,820: a permanent $1,400-a-month difference, $16,800 a year, for the rest of her life. Over a fifteen-year widowhood, before COLA, that is $252,000. The bridge cost the household about $300,000 of TSP draws, but it returned $38,700 a year while both were alive and protected her for the years she is likeliest to live alone.

One more federal-specific point. Since the Social Security Fairness Act took effect for 2024 benefits, the Windfall Elimination Provision and Government Pension Offset no longer apply. CSRS retirees and their spouses who were previously penalized now receive full spousal and survivor benefits, which makes the bridge newly relevant to households it never used to help. See the WEP/GPO repeal guide.

9. When the bridge is the wrong call

The bridge is a good default, not a universal rule. Claim early instead if:

• Your health or family history points to a shorter life, and you are single or your spouse has the higher benefit. The bridge is longevity insurance; if you have good reason to think you will not collect on it, do not buy it.
• Your TSP cannot fund the bridge and your baseline spending with margin. If bridging to 70 leaves you with less than five years of core expenses in reserve at 70, you are too close to the edge. Claim at FRA or a year or two later instead; every year of delay still helps.
• You have minor children or a dependent adult child. Children under 18 (or disabled adult children) can receive benefits on your record only once you claim. In some households that family benefit outweighs the delay credit.
• You are the lower earner in a couple. Your benefit is likely to be superseded by the survivor benefit. Claim it early and let your spouse’s benefit do the growing.
• You would need to sell stock funds in a down market to make the payments. If you did not segregate the bridge money in the G Fund and the market has fallen, pausing the bridge and claiming a year early is better than selling at the bottom. You can always claim later; you cannot un-sell.

And one myth to retire: the earnings test is not a reason to claim early or late. It applies only to benefits you are already receiving before FRA. If you are bridging and have not claimed, you can earn any amount without affecting the Social Security you will eventually receive. Only the FERS supplement is exposed.

10. Setting it up, step by step

• Pull your Social Security statement at ssa.gov/myaccount. Note the benefit at 62, 67, and 70. If you are married, pull both.
• Decide the bridge span. If you receive the FERS supplement, the TSP bridge starts at 62. If not, it starts when you retire or when penalty-free TSP access begins, whichever is later.
• Size the bridge: monthly check you are replacing × 12 × bridge years. Add 3% a year if you want the payments to keep pace with inflation.
• Move that amount into the G Fund by interfund transfer before the first payment. Leave the rest of the TSP in your long-term allocation.
• Set up monthly installments in the TSP for the bridge amount. Elect federal withholding that matches your expected bracket so you are not surprised in April; see retirement tax withholding.
• Each January: adjust the installment for inflation, rebalance so the remaining bridge years stay in G, and decide how much of the leftover 12% bracket to fill with a Roth conversion.
• Three months before 70: apply for Social Security online. Benefits can start the month you turn 70; there is no reason to delay past it.
• At 70: reduce or stop the TSP installments and move to your long-term withdrawal plan, keeping RMDs in view.

11. Frequently asked questions