Federal employees: how FEHB, GS pay, the TSP, and FERS fit together

Every fall, in Open Season (November 9 to December 14 this year), you can keep your plan or change it for the next year. For 2027 there are 118 plan options from 45 carriers: a handful of nationwide fee-for-service plans anyone can pick, plus the HMOs that serve your county. The government pays the lesser of 72% of the program-wide average premium or 75% of your plan's premium; you pay the rest, before tax, out of each paycheck. The premium is the number everyone compares and the one that says the least: the deductible, the out-of-pocket maximum, and the copays decide what a year actually costs.

Connected to: your pay (the premium is a line on the GS check), your retirement (you can keep FEHB for life if you were covered for the five years before you retire), and, if you retired from the military, TRICARE (you can suspend FEHB to use it and come back in an Open Season).

Dental and vision are a separate program with its own plans and its own enrollment site, BENEFEDS, on the same Open Season dates. You pay the whole premium, before tax while you work; there is no government share. For 2027 there are 21 dental options from 11 carriers and 10 vision options from 5, and a dental premium depends on a rating region that each carrier draws its own way, so two neighbors can pay different rates for the same plan. An Open Season change takes effect January 1. Unlike FEHB there is no five-year rule: coverage follows you into retirement on an immediate annuity however long you had it.

Connected to: your pay (the premium comes out before tax), FEHB (many health plans carry some dental and vision of their own, which pays first), and a military retirement (retirees and gray-area reservists can buy FEDVIP dental, and vision if they are in a TRICARE plan).

Fifteen grades, ten steps each, one base table, and a locality percentage on top that depends on where you work. A step comes with time (one, two, or three years at each, faster with a quality step increase), a grade with a promotion. The table is published by OPM each January.

Connected to: everything below. The FEHB premium and the TSP contribution are percentages and dollars taken from this number, and the high-3 that sets a FERS annuity is the average of your three highest consecutive years of it.

The agency puts in 1% of your pay whether you contribute or not, then matches dollar for dollar on your first 3% and fifty cents on the dollar on the next 2%. Contribute 5% and the agency adds 5%. The match is figured every pay period, so hitting the annual limit early forfeits the match for the rest of the year. The 2026 limits are $24,500, plus $8,000 if you are 50 or older, or $11,250 at ages 60 to 63. The automatic 1% vests after three years; your own money and the match are yours from day one.

Connected to: your pay (a percentage of it), FERS (the TSP is one of the three legs), and a military past (a uniformed-services TSP account can be combined with the civilian one, except tax-exempt combat-zone money in the traditional balance).

The calculator is built around the Blended Retirement System match, which has the same shape as the FERS match: 1% automatic, 3% matched in full, 2% matched by half.

The annuity is 1% of your high-3 for each year of service, or 1.1% if you retire at 62 or later with at least 20 years. The minimum retirement age is 57 for anyone born in 1970 or later (55 to 57 for earlier years), and you need 30 years at that age, 20 at 60, or 5 at 62 for an unreduced annuity. Retire before 62 on an immediate annuity and the FERS Supplement bridges you to Social Security. You pay 0.8%, 3.1%, or 4.4% of pay toward it depending on when you were first hired. The official estimate comes from your agency's HR office, and OPM pays it. The 2025 reconciliation law (Public Law 119-21, July 4, 2025) left FERS contributions, the annuity formula, and the supplement as they were; the House-passed versions of those changes were dropped before passage. What it did add is family member eligibility verification in FEHB, which starts with this Open Season (OPM Open Season highlights, PDF).

Connected to: your pay (the high-3), the TSP and Social Security (the other two legs), FEHB (the five-year rule rides on the retirement date), and military service (below).

Buying back your time. A deposit of 3% of the military basic pay you earned adds those years to your FERS annuity. Interest starts after your first years in federal service, so early is cheaper. If you draw military retired pay you generally must waive it for the credit, unless the retired pay is for a combat-related disability or a Reserve retirement; most retirees keep the pension and skip the deposit. DFAS estimates the earnings (form RI 20-97), your agency processes the deposit (SF 3108).

TRICARE and FEHB. A military retiree in a federal job can carry both, or suspend FEHB to use TRICARE and re-enroll in any Open Season. Cancelling FEHB as an annuitant is permanent, suspending is not.

Connected to: the retired pay estimator (what the military pension is worth beside the civilian one) and the FEHB comparison's rule box (OPM's wording on suspending).