Inputs you will enter
- Your FEHB plan and enrollment typePick from the current OPM premium table, or type your monthly share.
- Annuitant or employeeAnnuitants pay monthly; employees pay biweekly.
- Income from two years agoYour modified adjusted gross income and filing status, for the IRMAA tier.
- Plan Part B reimbursementOptional, from your plan's brochure.
- SpouseOptional, to add a second Part B premium.
How we compute it
We read your FEHB premium from OPM's current table (OPM, retrieved 2026-07-05) and annualize it. For the Part B path, we add the standard Part B premium and the IRMAA amount for your income tier, both from our IRMAA brackets page with their dates, then subtract any reimbursement you entered. IRMAA uses your tax return from two years before the premium year.
We do not estimate out-of-pocket costs. Those depend on your health and your plan's rules, and they are where Part B can save or cost you money.
A worked example
Your FEHB share is $300 a month, $3,600 a year. Adding Part B at the standard premium (the tool fills the current figure and date) raises the yearly total by twelve times that premium, minus any reimbursement your plan pays. If your income puts you in an IRMAA tier, that surcharge is added too. Educational estimate on the assumptions shown.
What to do with your numbers
Read FEHB and Medicare at 65 for how the two coordinate, and keeping FEHB in retirement for the 5-year rule. Compare plans on the FEHB premiums page.
This decision is hard to undo because of the late-enrollment penalty.
FFEBA is an education organization. If you want someone to look at your own numbers, we can match you with a Federal Retirement Consultant (FRC), a professional trained on federal benefits. The FRC designation is listed with FINRA. The first review is free, nothing is booked until you choose a time, and you are never obligated to work with anyone we introduce. Get matched with an FRC.
Questions about this calculator
Do federal retirees have to take Medicare Part B?
Most FEHB retirees are not required to enroll in Part B to keep FEHB. It is a choice with a cost on both sides. Postal Service retirees in the Postal Service Health Benefits program have their own Part B rules. Check OPM's PSHB pages if that is you.
What happens if I skip Part B at 65 and want it later?
Medicare charges a late-enrollment penalty added to your Part B premium for life, generally 10 percent for each full 12-month period you could have had Part B and did not. FEHB coverage as a retiree does not give you a special enrollment period. Coverage through current employment can.
Does FEHB pay less once I have Medicare?
When Medicare is primary, many FEHB plans waive deductibles and coinsurance for services Medicare covers, and some offer Part B premium reimbursement or Medicare Advantage options. What your plan does is in its brochure; this tool shows premiums only.
What is IRMAA?
IRMAA is an extra amount added to Medicare Part B and Part D premiums for people whose income from two years earlier was above set thresholds. Our IRMAA brackets page lists the current tiers with their source and date.
Reviewed by the FFEBA education team. Last reviewed October 2026.
Sources
- U.S. Office of Personnel Management, FEHB premiums 2026 (FFS and HMO rate files), retrieved 2026-07-05
- U.S. Office of Personnel Management, FEHB and Medicare, retrieved 2026-07-05
- Social Security Administration, Medicare premiums and IRMAA
Every government figure on this page carries its source and retrieval date. Worked examples are educational estimates on the assumptions shown, not a projection of any person's benefit. FFEBA is an education organization, not a financial advisor.
