BRS vs. High-3: Which Military Retirement System You're Under and What It Pays
Your DIEMS date, not your preference, decides whether you retire under the Blended Retirement System or legacy High-3 — and the gap between a 2.0% and a 2.5% multiplier is worth hundreds of dollars a month for life. Here's the math, plus the two BRS benefits legacy retirees never get.
Published 2026-08-12 · Updated 2026-08-12 · PCS Calculator · Source: https://www.pcscalculator.net/blog/brs-vs-high-3-military-retirement-explained
Last reviewed August 2026
Most service members can't choose their retirement system. It was assigned the day they entered service, based on their DIEMS date (Date of Initial Entry to Military Service), and it determines two things that matter enormously: how much your pension pays if you serve 20 years, and whether you walk away with anything if you don't. The two systems in play today are the legacy High-3 plan and the Blended Retirement System (BRS). Here's how each one calculates retired pay, what the difference is worth in real dollars, and which BRS features have no legacy equivalent. You can model the savings side of either system with our TSP calculator.
Which System You're Under
This is determined by your DIEMS date, not by your current unit, component, or contract:
- DIEMS on or after January 1, 2018: You are under BRS automatically. There was no election to make and no way to opt out.
- DIEMS before January 1, 2018: You remain under the legacy High-3 system, unless you actively opted into BRS during the 2018 open season.
That open season ran from January 1 through December 31, 2018, and it is permanently closed. To have been eligible, an active component member needed fewer than 12 years of service as of December 31, 2017; a National Guard or Reserve member in a paid status needed fewer than 4,320 retirement points as of that same date. Members who met the criteria on December 31, 2017 had the full calendar year to decide, even if they crossed the threshold during 2018. If you did not opt in then, you cannot switch now — there is no second window, and no branch has authority to grant one.
(Two older plans still exist at the margins: members with a DIEMS date before September 8, 1980 fall under Final Pay, and some who entered service on or after August 1, 1986 elected the Career Status Bonus with REDUX at 15 years of service. Both are outside the scope of this article, but if either describes you, your multiplier is not the 2.5% discussed below — check with your finance office.)
The Pension Formula: 2.5% vs. 2.0%
Both systems use the same starting point, called the retired pay base: the average of your highest 36 months of basic pay. This is where the name "High-3" (also written "High-36") comes from. For most careers those 36 months are simply the final three years of service, since basic pay generally rises with each promotion, longevity step, and annual raise. Note that this average is built from basic pay only — BAH, BAS, special pays, and bonuses are not part of it.
From there, the two systems diverge on a single number, the multiplier:
- Legacy High-3: 2.5% × years of service × high-36 average
- BRS: 2.0% × years of service × high-36 average
At a 20-year retirement, that produces 50% of your high-36 under legacy High-3 and 40% under BRS. The gap scales with time served: at 24 years it's 60% versus 48%, and at 30 years it's 75% versus 60%. In percentage terms, the BRS pension is always 20% smaller than the legacy pension for the same career length — that is the trade the system makes in exchange for the government TSP contributions described below.
What the Difference Looks Like in Dollars
The multiplier gap only becomes real when you attach it to a pay figure. For reference, the 2026 DFAS basic pay tables — the same tables behind our military salary calculator — put an E-7 with over 20 years at $6,245.70 per month and an O-4 with over 20 years at $10,509.90 per month. Your actual high-36 average will be somewhat lower than your final monthly rate, because it blends in the two prior years at lower longevity steps and pre-raise pay tables. So the round numbers below are illustrative averages chosen to keep the arithmetic clean, not predictions of any individual's retired pay.
Example 1 — a senior enlisted retirement, assuming a high-36 average of $6,000/month at 20 years:
- Legacy High-3: 2.5% × 20 × $6,000 = 50% = $3,000 per month
- BRS: 2.0% × 20 × $6,000 = 40% = $2,400 per month
- Difference: $600 per month, or $7,200 per year
Example 2 — a field grade officer retirement, assuming a high-36 average of $10,200/month at 20 years:
- Legacy High-3: 50% = $5,100 per month
- BRS: 40% = $4,080 per month
- Difference: $1,020 per month, or $12,240 per year
Serving longer widens the gap rather than closing it. Take the same $6,000 high-36 average out to 24 years and legacy pays 60% ($3,600) against BRS at 48% ($2,880) — a $720 monthly difference. And because military retired pay is a lifetime annuity that begins immediately at an active duty retirement, these differences run for decades. What they do not account for is the BRS side of the ledger: the TSP balance a BRS member accumulates over the same career, which the legacy member never receives. Whether that balance closes the gap depends on contribution rate, market returns, and years served, so it's worth modeling your own numbers rather than trusting a rule of thumb.
The 20-Year Cliff
The pension multiplier is only half the comparison, and for most service members it isn't the important half. The legacy High-3 pension is all-or-nothing at 20 years. Serve 19 years and 11 months and separate voluntarily, and the pension pays nothing at all — there is no partial benefit, no reduced annuity, no refund. (Disability retirement and any Temporary Early Retirement Authority a service is specifically authorized to offer are separate programs with their own rules.) Since the majority of people who enter the military separate well before 20 years, the legacy system's headline 50% never reaches them.
BRS was designed around that fact. In exchange for the smaller multiplier, every BRS member gets government money in a Thrift Savings Plan account: an automatic contribution equal to 1% of basic pay beginning 60 days after entering service, plus up to 4% in matching once you complete two years of service. The automatic 1% vests at two years of service; your own contributions are yours immediately. Leave at six years, and that balance still goes with you. Both the automatic and matching contributions run through the end of the pay period in which you reach 26 years of service, then stop. For the full mechanics of the tiered match and what it costs to under-contribute, see The Blended Retirement System and TSP Matching Explained.
Continuation Pay: BRS Only
Continuation pay is a mid-career cash bonus that exists solely under BRS — legacy High-3 members are not eligible for it under any circumstance. By statute it is payable to BRS members who have completed not less than 7 and not more than 12 years of service, in exchange for an additional service obligation.
The statutory floors on the payment are 2.5 times monthly basic pay for active component members and 0.5 times monthly basic pay for reserve component members. Those are minimums, not fixed amounts — each service sets its own multiplier, its own eligibility window inside the statutory range, and its own timing, and it re-sets them annually. Some branches have paid well above the floor in past years and have since narrowed both the multiplier and the window, so last year's rate tells you nothing reliable about this year's.
The obligation attached to the money is firmer. Accepting continuation pay commits you to four additional years of service, active or reserve, and that commitment generally runs concurrently with any obligation you already carry unless your branch specifies otherwise. Because the payment amount and the eligibility window still vary by branch and by calendar year, do not plan around a multiplier you read anywhere — including here. Check your branch's current-year continuation pay message or policy memo and confirm the terms with your finance office before you sign anything.
The Lump Sum Option: BRS Only
BRS retirees have a choice at retirement that legacy retirees do not: they may take part of their retired pay up front as a lump sum. The election is for either 25% or 50% of the value of their retired pay, and it can be received as a single payment or as up to four equal annual installments.
The trade-off is steep, and it works in two ways. First, the lump sum is discounted to present value using a personal discount rate that the Department of Defense publishes each June — for calendar year 2026 that rate is 6.46%. A high discount rate means the up-front payment is worth substantially less than the sum of the payments you're giving up. Second, your monthly retired pay is reduced for the entire period covered by the election: take 25% and you receive 75% of your monthly retired pay; take 50% and you receive half. That reduction lasts until you reach full Social Security retirement age — age 67 for anyone born in 1960 or later — at which point your monthly retired pay automatically reverts to the full, undiscounted amount.
For someone retiring at 42, that means roughly 25 years of reduced monthly income in exchange for a discounted payment today. The option can make sense in specific circumstances, but it is a genuine financial decision rather than free money, and it is irrevocable once made. Run the numbers against the current-year discount rate before electing it.
Cost-of-Living Adjustments
Here the two systems are the same. Retired pay under both legacy High-3 and BRS is adjusted annually for inflation based on the Consumer Price Index, with no reduction — the 2026 adjustment was 2.8%. Because both plans receive the identical full COLA, inflation protection is not a factor when comparing them. (Members under CSB/REDUX are the exception, receiving a reduced COLA until an age-62 catch-up.)
Summary: BRS vs. High-3 at a Glance
| Feature | Legacy High-3 | Blended Retirement System |
|---|---|---|
| Who's covered | DIEMS before Jan 1, 2018 (no opt-in) | DIEMS on/after Jan 1, 2018, or opted in during 2018 |
| Pension multiplier | 2.5% per year of service | 2.0% per year of service |
| Retired pay base | Average of highest 36 months of basic pay | Average of highest 36 months of basic pay |
| Pension at 20 years | 50% of high-36 | 40% of high-36 |
| Pension at 24 years | 60% of high-36 | 48% of high-36 |
| If you separate before 20 years | No pension, nothing | Vested TSP balance is yours to keep |
| Automatic TSP contribution | None | 1% of basic pay, starting 60 days after entry |
| TSP matching | None | Up to 4% after 2 years of service |
| Government TSP contributions end | N/A | End of the pay period at 26 years of service |
| Continuation pay | Not eligible | Between 7 and 12 years of service, per branch policy; 4-year service obligation |
| Lump sum option at retirement | Not available | 25% or 50%, reduced monthly pay until full SSA age |
| Annual COLA | Full CPI-based adjustment | Full CPI-based adjustment |
Figures here reflect 2026 rates and current policy. Pay tables, COLA, and the lump sum discount rate change every year, and continuation pay terms change by branch — verify current numbers at tsp.gov and DFAS, or with your finance office, before making a decision.
Frequently Asked Questions
Can I switch from High-3 to BRS now?
No. The opt-in window ran only from January 1 through December 31, 2018, and it is permanently closed. If you were eligible then and did not opt in, you remain under legacy High-3 for the rest of your career. If your DIEMS date is on or after January 1, 2018, you are under BRS and were never able to opt out.
How do I find out which retirement system I'm under?
Your DIEMS date is the deciding factor, and it appears on your Leave and Earnings Statement and in your service record. A DIEMS date on or after January 1, 2018 means BRS. Earlier than that means legacy High-3, unless you elected BRS during the 2018 open season — that election is also recorded in your pay record. Your finance office can confirm both.
Is High-3 better than BRS?
It depends entirely on how long you serve. For someone who completes a full 20-year career, legacy High-3 pays a pension 20% larger for the same years of service. For the much larger group who separate before 20 years, legacy pays nothing at all while BRS members keep their vested TSP balance. BRS also adds continuation pay and the lump sum option. Since almost no one can choose between them today, the practical question is how to get the most out of the system you are already in.
Does the High-3 average include BAH and BAS?
No. The retired pay base is the average of your highest 36 months of basic pay only. Housing and subsistence allowances, special and incentive pays, and bonuses are excluded from the calculation under both systems.
Do legacy High-3 members get TSP matching?
No. The automatic 1% contribution and the matching contributions are BRS-only benefits. Legacy High-3 members can still contribute their own money to the TSP and receive the same investment options and tax treatment, but the government does not add anything on top.
Related Articles
- The Blended Retirement System and TSP Matching Explained: How to Get the Full 5% — the contribution side of BRS in detail
- PCS During Separation or Retirement: What You're Entitled To — your final move entitlements
- PCS Advance Pay: How Much You Can Request and How It Gets Repaid
- PCS Taxes Explained: What Is and Isn't Taxable for Military Moves