Medicare Medigap Calculator - Basic
If you are using or evaluating Medicare Supplemental Insurance, also called Medigap, easily calculate your monthly and annual costs for the Medigap plan you select, optionally including Part D Prescription Premium, Part B and IRMAA surcharges if applicable. View the Medigap Cost chart for concise summary of premium cost allocation.
Advanced Medigap Calculator automatically estimates Part B premium, and IRMAA surcharges if applicable
Important: This calculator is not designed for calculating Medicare Advantage Plans.
Medigap is also called Supplemental Insurance. Throughout this calculator, the two are used interchangeably. See sidebar for abbreviations, including IRMAA.
Entry Fields
Only two of the calculator criteria fields are required: Plan Year and Medigap Monthly Cost. This way, you can choose to zoom into just Medigap plan costs; Or, you can add additional Medicare costs, to get a fuller picture of how much Medicare will cost you annually. The Advanced Medigap Calculator can fill in many of the Medicare premium costs, such as Part B, if the calculator supports the plan year.
Premium Plan Year - Enter the year for which you are calculating supplemental insurance. For instance, if you are evaluating or have signed up for a Medigap plan for 2024 Medigap, enter 2024; All Medicare related costs on the entry form should be based on 2024 Premium rates.
Medigap Plan/Company - You can use this optional field for the name of the plan and/or the insurance company which provides the Medigap plan. What you enter here is used descriptively on the calculator results.
Medigap Premium (Monthly Cost) - Enter the monthly premium cost of Medigap for the plan year.
Part D Company - Optional, for calculator results; To indicate Part D company and/or its plan name.
Part D Premium (Monthly Cost) - Enter the monthly premium cost of the Part D Prescription Drug plan you are considering or have enrolled in for the plan year. This field is optional.
Part B Premium Plan (Monthly Cost) - Enter the monthly cost of Part B. For example, in 2025, the Part B premium was $185.00 per month, whereas in 2024 it was $174.70 per month.
Part B IRMAA Surcharge - If you are subject to an IRMAA surcharge for the premium year, enter the monthly Part B surcharge cost. If IRMAA does not apply to you for the premium plan year, leave this field empty, or enter zero.
SSA determines and notifies you if IRMAA Parts B and D surcharges apply to you in a given year, based on MAGI and filing status from two years prior to the premium year, including what the monthly surcharges are based on the IRMAA sliding scale tables for the premium year. In 2024, approximately 7 percent of Medicare recipients payed IRMAA surcharges.
Part D IRMAA Surcharge - If subject to IRMAA Part D surcharge for the premium year, enter the monthly cost. If not applicable, leave this field empty, or enter zero.
About Calculator
Medigap is an option many Medicare beneficiaries use along with Original Medicare (Parts A and B). When on a Medigap plan, one also purchases a Part D Prescription plan separately. Both Medigap and Part D stand-alone plans are sold by separate private insurance companies.
With this calculator, you can determine your annual cost for a Medigap plan you are considering, or are already using.
You can opt to add in other Medicare costs, including the standard Part B premium, as well as the Part D plan you've selected, and IRMAA surcharges if they are applicable to you for the premium year.
If it is near the end of the current year, and you want to project for the next year but the IRMAA sliding tables have not yet been determined by CMS, or other premium price updates are not yet officially available, you can use this calculator by entering projected costs that may have been announced (e.g. Part B new rate, per CMS), or using this year's costs increased by the rate of inflation. Similarly, if our calculators are not yet updated with more recent Medicare data, you can manually input new rates.
Cost Allocation Pie Chart
This calculator will show monthly and annual costs for Medigap and other Medicare costs you've entered. It also includes circular chart where you can view the distribution of these costs, to easily see expense allocations. The pie chart only shows non-zero costs you have provided.
I'm Married - Does My Spouse Pay the Same Premiums?
When it comes to Medicare, every Medicare beneficiary is an individual, meaning that if you are married, you and your spouse pay premiums separately. Whether you pay the same rate for certain premiums depends: read on.
Part B Rate is the Same
Medicare Beneficiaries pay the same rate for Part B, which is for out-patient care such as doctor's visits and preventative care, regardless of marital status. For example, in 2025, Part B was $185 per person. So in 2025, each spouse would pay $185.
IRMAA Surcharge is the Same (if applicable)
When it comes to IRMAA, and SSA determining if your income (MAGI) meets a surcharge status in a given premium year, if you and your spouse filed your tax return (2 years prior to the premium year) Married Filing Jointly, then the IRMAA sliding scale tables for Married Filing Jointly would be used. If it turns out your income was high enough to require IRMAA surcharges, the Part B and Part D surcharge amount you and your spouse pay would be the same amount, but you both would pay it.
For example, if in 2025, based on MAGI from your 2023 tax return filed Married Filing Jointly, SSA determines your IRMAA is in the lowest tier, the Part B surcharge would be $74 a month, and the Part D surcharge would be $13.70. You and your spouse would both pay the same amount, but separately.
Medigap Plan Rates will likely differ
Even if you and your spouse chose the same Medigap Plan - such as Plan G - it is more than likely your monthly rates will differ. For example, premiums for women tend to be slightly lower than for men.
Moreover, you and your spouse may opt for different Medigap plans, or use different companies; Or one of you may opt into Medigap, and the other chooses a Medicare Advantage plan.
Part D Plan Rate may Differ
Per Medicare, if you are on a Medigap sold after 2005, it does not include a Part D Prescription plan. Part D is also sold by private insurance companies. The rates you and your spouse pay can vary if you choose different companies, or different plans offered by the same company.
If one spouse is on Medicare Advantage which includes Part D, that spouse won't pay Part D monthly. Or, both spouses can be on Medicare Advantage - the same or different companies - where neither pays Part D.
As this shows, there are many variations. The important point to remember is that each spouse pays separately; In some cases, like for IRMAA, the rates can be the same, in others they can differ.
- Medicare (https://www.medicare.gov/)
- Social Security Administration (SSA) (https://www.ssa.gov/)
Disclaimer: All data calculated or presented, including, but not limited to premiums and surcharges, is based on the criteria you provided and/or information available from the Social Security Administration (SSA) or Medicare, such as the Income-Related Monthly Adjustment Amount (IRMAA) sliding scale tables and Part B premiums. By using this calculator, you understand and agree that all calculations are only estimates, and can differ from actual information that SSA or Medicare provides to you which shall always takes precedence. It is your sole responsibility to contact SSA or Medicare for any questions you may have about Medicare, related premiums, or IRMAA. binfy.com has no affiliation whatsoever with any insurance company or with any government entity. This calculator, and all information on it, is not intended to and does not provide any advice, recommendation or endorsement of any insurance plan or insurance company. This calculator is based on Medicare and IRMAA in the United States, and is not applicable to any other country.