Terms & Definitions
Master the language of federal benefits. A complete glossary of retirement, insurance, and investment terminology.
A
Accepting Assignment
When a doctor or supplier agrees to accept the Medicare-approved amount as full payment for covered Part B services.
B
Basic Benefit Plan
The defined-benefit pension portion of FERS. It provides monthly annuity payments after retirement based on age, years of service, high-3 average salary, and the applicable pension formula.
C
C Fund
The TSP Common Stock Index Investment Fund. It is designed to track the performance of a broad U.S. large-company stock index.
Civil Service Retirement System (CSRS)
A defined-benefit federal retirement system predating FERS, closed to new employees since January 1, 1987. CSRS employees generally pay no Social Security tax and receive no agency TSP match, unlike FERS, which combines a smaller pension with Social Security and matched TSP contributions.
D
12(d) Coverage
A common shorthand for special retirement coverage under FERS statutory references.
E
Early Retirement
A retirement that begins before normal voluntary retirement eligibility. In federal benefits, this can refer to VERA, discontinued service retirement, special provision retirement, or certain TSP/IRS withdrawal situations.
F
F Fund
The TSP Fixed Income Index Investment Fund. It is designed to track a broad U.S. bond index.
Federal Employees' Group Life Insurance (FEGLI)
Group term life insurance for federal employees and retirees, consisting of Basic coverage plus three optional layers (Options A, B, and C). OPM administers the program; claims are handled by the Office of Federal Employees' Group Life Insurance (OFEGLI), a unit of MetLife.
Federal Employees Health Benefits Program (FEHB)
The largest employer-sponsored group health insurance program in the country, covering active federal employees, eligible retirees, and their families. Coverage can continue into retirement at the same government contribution rate if the retiree was enrolled for the 5 years immediately before retiring. Since January 1, 2025, Postal employees and Postal annuitants are covered instead by PSHB, a separate program with its own plans and its own Medicare Part B requirement.
Federal Employees Retirement System (FERS)
The three-part retirement plan covering most federal civilian employees hired since 1987, combining a Basic Benefit pension, Social Security, and the Thrift Savings Plan (TSP). Unlike the pension, the Social Security and TSP portions can move with an employee to a subsequent job.
G
G Fund
The TSP Government Securities Investment Fund. It invests in special U.S. Treasury securities issued only to the TSP and is designed to preserve principal while earning interest.
H
High-3 Average Salary
The highest average basic pay earned during any three consecutive years of creditable federal service. High-3 is a key part of the FERS and CSRS pension calculation.
I
I Fund
The TSP International Stock Index Investment Fund. It is designed to track international stock market performance outside the United States.
J
No terms currently listed for the letter J. This section is intentionally left blank.
K
No terms currently listed for the letter K. This section is intentionally left blank.
L
L Fund
A TSP Lifecycle Fund. L Funds are diversified funds that automatically adjust their investment mix over time based on a target retirement date or withdrawal timeline.
M
Mandatory Retirement
A required separation age for certain federal employees, including some law enforcement officers, firefighters, air traffic controllers, nuclear materials couriers, and Customs and Border Protection officers.
Medicare
The federal health insurance program for people age 65 and older and for certain younger people with disabilities. It has four parts — Part A (hospital), Part B (medical), Part C (Medicare Advantage), and Part D (prescription drugs) — and for federal retirees it coordinates alongside FEHB rather than replacing it. Part B is optional for most FEHB retirees, but Postal annuitants under PSHB are generally required to enroll in it.
N
Net Annuity
The annuity payment after deductions.
O
OASDI
Old-Age, Survivors, and Disability Insurance. The Social Security portion of payroll taxes and Social Security benefits.
Office of Personnel Management (OPM)
The federal government's chief human resources agency. OPM administers federal retirement benefits (CSRS and FERS) and manages employee insurance programs, including FEHB, FEGLI, and FEDVIP.
P
Postal Service Health Benefits Program (PSHB)
The health insurance program that replaced FEHB for Postal employees, Postal annuitants, and their eligible family members on January 1, 2025. It is administered by OPM and follows most FEHB rules — including the 5-year rule for carrying coverage into retirement — but has its own plan lineup and one major difference: Postal annuitants who are entitled to premium-free Medicare Part A generally must also enroll in Part B to keep PSHB coverage. A small number of exemptions apply, and dropping Part B later can end PSHB coverage permanently.
Q
Qualified Distribution
A distribution that meets tax-law requirements for favorable tax treatment. For Roth accounts, qualified distributions generally require meeting age and holding-period rules.
R
Reassignment
Movement of an employee to another position without promotion or change to lower grade.
S
S Fund
The TSP Small Capitalization Stock Index Investment Fund. It is designed to track U.S. stocks not included in the large-company index tracked by the C Fund.
Service Computation Date (SCD)
The date used to calculate a federal employee's creditable service. There are several SCDs for different purposes — leave accrual, retirement eligibility, RIF retention, and within-grade increases — and they don't always match, so relying on the wrong one (like SCD-Leave for a pension estimate) can produce an inaccurate result.
Special Retirement Supplement (SRS)
Also called the FERS annuity supplement — a bridge benefit paid to certain FERS employees who retire before 62 on an immediate, unreduced annuity, approximating the Social Security they earned during federal service. It is taxable, receives no COLA, is reduced by the Social Security earnings test, and stops at 62 regardless of whether Social Security has been claimed.
T
Tax-Exempt Balance
A TSP balance from tax-exempt contributions, usually related to uniformed service in a combat zone tax exclusion situation.
Thrift Savings Plan (TSP)
The federal government's defined-contribution retirement savings plan, similar to a private-sector 401(k). FERS participants receive an automatic 1% agency contribution plus matching up to 5% of pay, invested across the G, F, C, S, and I core funds or the age-based Lifecycle (L) funds.
U
Unpaid Compensation
Salary or other pay owed to a federal employee at death. It can be paid according to a beneficiary designation or order of precedence.
V
VA Disability Compensation
A tax-free benefit paid by the Department of Veterans Affairs to eligible veterans with service-connected disabilities. It is separate from FERS, TSP, FEHB, military retired pay, and Social Security.
W
Waiver of FEGLI
An election to decline FEGLI coverage. This matters because getting coverage back later may require a qualifying event, open season, or medical underwriting.
Windfall Elimination Provision (WEP)
A Social Security rule that used to reduce benefits for retirees — including many CSRS retirees — who also received a pension from work not covered by Social Security. The Social Security Fairness Act repealed WEP (and the related Government Pension Offset) in January 2025 for benefits payable after December 2023, so it no longer reduces anyone's Social Security benefit, though it may still appear in older materials.
X
No terms currently listed for the letter X. This section is intentionally left blank.
Y
Year of Service
A period of creditable employment used to determine federal retirement eligibility and annuity computation. Not every type of service counts the same way.
Z
No terms currently listed for the letter Z. This section is intentionally left blank.