The arithmetic behind a military pension is not secret, but which formula applies to a given service member is the part people get wrong. Retired pay turns on three inputs, a multiplier, the years of service, and an average of the highest basic-pay years, and the multiplier itself depends on when the member entered service. A legal assistance attorney is most useful here not as a calculator but as the person who confirms which system a member is actually in before any number gets trusted.
The shared building block: High-36
Both current retirement systems start from the same base, often called High-36: the average of a member’s highest 36 months of basic pay. That figure, not final pay or gross pay, is what the multiplier is applied to. Getting this base right matters, because every later number is a percentage of it.
Two systems, two multipliers
The difference between the systems is the multiplier per year of service.
- Legacy (High-3) system. For eligible members under the older system, retired pay is 2.5% times each year of service, applied to High-36. At 20 years that produces 50% of High-36 as a defined benefit.
- Blended Retirement System (BRS). For members under BRS, the multiplier is 2.0% per year of service. At 20 years that produces 40% of High-36 as the defined benefit, with the difference offset by Thrift Savings Plan contributions and government matching that the legacy system does not include.
So a 20-year retiree’s pension is 50% of High-36 under the legacy formula and 40% under BRS. Which one applies depends on the member’s service-entry date and, for a window of members, whether they opted in to BRS. That eligibility question is exactly where a misunderstanding can throw off an estimate by a meaningful margin.
Where an attorney fits
Most members can run the numbers themselves: the Department of Defense publishes official High-3 and BRS calculators. The legal-assistance value shows up when retired pay intersects with a legal decision, an estate plan, a divorce, or a benefits dispute, where the pension figure becomes an input to something else. There, confirming the correct system, the correct High-36 base, and the correct years of creditable service keeps the downstream document honest.
A practical note worth separating out: calculating a pension is not the same as dividing one. How retired pay is computed is one question; how a court may split it in a divorce is a different body of law with its own rules. An attorney advising on a calculation keeps those two questions distinct so the member knows which one they are actually asking.
Take a member nearing twenty years who asks what their pension will be: the attorney can walk through whether they fall under the legacy system, at roughly fifty percent, or the Blended Retirement System, at roughly forty percent, while leaving the actual figure to the official calculators.
The distinction worth carrying away is between calculating a pension and relying on that figure. The formula itself is fixed and the official calculators are reliable; the mistakes come from applying the wrong system or the wrong High-36 base. Pin down those two inputs, and the number sitting underneath every later decision will hold.
Frequently Asked Questions
Is military retired pay taxed?
Military retired pay is generally subject to federal income tax. State tax treatment varies widely, and a number of states exempt military retired pay in whole or in part.
Can retired pay be reduced after it starts?
Yes. In certain situations, such as a waiver of retired pay to receive VA disability compensation or a court-ordered division, the amount a retiree actually receives can change.
How is the older “final pay” system different from High-3?
The earliest entrants fell under a “final pay” formula based on final basic pay, while the High-3 and High-36 systems average the highest 36 months of basic pay. Which system applies depends on the member’s service-entry date.
This article is general information about how military retired pay is calculated. It is not legal or financial advice and does not create an attorney-client relationship. Formulas, eligibility, and figures depend on individual service history and can change. Service members should use the official Department of Defense calculators and consult their legal assistance office for guidance on their situation.
Sources