Advanced Medigap Calculator (with IRMAA)

Calculate how much the Medigap (supplemental insurance) plan you're using or evaluating will cost for the premium year, along with related medicare costs, including Part D Prescription Drug premium. This Calculator can also automatically determine Part B and if IRMAA surcharges apply using MAGI and tax filing status. More below.

A basic version of this calculator is available, where you can enter Medigap Plan, Part D, and other Medicare costs manually.

Important: This calculator is not designed for calculating Medicare Advantage Plans.

Premium Plan Year:

Premium year for Medigap, IRMAA, other Medicare costs

Medigap Plan/Company:

(Optional) Supplemental insurance plan name or company

Medigap Premium: $

Monthly Medigap Plan Cost

Part D Company:

(Optional) Part D Company Name

Part D Premium: $

Monthly Part D Premium Plan Cost

Calculator retrieves Part B Premium and determines IRMAA B and D Surcharges, if applicable, for premium year and supported see below.

MAGI: $

MAGI Amount 2 years before premium year

Tax Filing Status:

How tax return filed in MAGI Year

If either field is blank, IRMAA info is not retrieved.

See: Definitions Sidebar which details several abbreviations used on this calculator, such as IRMAA and MAGI.

Entry Fields

Premium Plan Year - Enter the year for which you are calculating Medigap insurance. For instance, if you are evaluating or have signed up for a Supplemental Insurance for 2025, enter 2025.

All other Medicare related costs you enter (e.g. Part D premium) should be for the same year. In addition, the year you enter here is also used to estimate IRMAA, so it corresponds to the IRMAA threshold tables for the premium year.

Medigap Plan Name/Company - While this field is optional, it is helpful as it is used on the results to identify the plan. You can use an abbreviation, such as the company name or abbreviation and the Medigap Plan.

Medigap Premium (Monthly Cost) - Enter the monthly premium cost of the Supplemental Plan for the premium year.

Part D Company/Plan - 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.

MAGI and Tax Filing Status: The following two fields can be used to get an estimate for Part B and IRMAA Part B and D surcharges, if applicable based on MAGI and tax filing status for two years prior to the premium year entered earlier on the form. If you opt to use this feature, enter both MAGI and Tax Filing Status.

MAGI - Enter Modified Adjusted Gross Income for 2 years prior to the premium year. MAGI is calculated by adding two lines from tax form 1040. For more information on how you can calculate MAGI, see the sidebar.

Filing Status - Select the filing status you used on the tax return 2 years prior (i.e. the same return for which you are entering MAGI just above). This field determines which of the three IRMAA sliding scale tables is used.

This calculator does not calculate MAGI. You will need to enter it. You can determine MAGI from your tax return (for 2 years prior to the IRMAA/premium year). As per Social Security Admin (SSA), MAGI is the sum of: beneficiary's Adjusted Gross Income (AGI), which is line 11 on IRS tax form 1040, plus tax-exempt interest income, which is line 2a of IRS Form 1040.

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 Drug plan separately. Both Medigap and Part D plans are sold by private insurance companies. In addition, most people pay Medicare Part B monthly; And, approximately 7 percent (as of 2024) of those on Medicare pay IRMAA surcharges.

With this calculator, you can get a good approximation of how much your Medigap Plan, and optionally Part D Prescription Plan, will cost you annually. In addition, you can opt to add in the Part B premium, and IRMAA surcharges if they are likely applicable to you for the premium year.

If you do choose to include Part B, and get an estimate of IRMAA, these are automatically calculated based on MAGI and tax filing status outlined above, under entry fields.

If you want to what-if calculate for the next year but the IRMAA sliding tables, or Part B premium, have not yet been officially released by CMS, you can use the Basic Medigap Calculator, where you can manually enter projected costs for monthly premiums. Similarly, if our calculators are not yet updated with more recent Medicare data, you can manually input new rates using the basic calculator.

Cost Allocation Pie Chart

In addition to showing monthly and annual costs for Medigap and other Medicare premiums, this calculator includes a circular chart showing the distribution of these costs. The pie chart only shows non-zero costs.

Therefore, if you calculate for IRMAA but do not meet the minimum threshold, IRMAA surcharges are not included on the chart.

More Information on Medicare Part B and IRMAA

Our IRMAA Calculator is similar to parts of this calculator: it calculates Part B, and IRMAA surcharges, if applicable, for the specified premium year, using MAGI and Tax Filing Status, in the same way as this calculator.

That calculator also contains more information about Part B and IRMAA, including when and why IRMAA was enacted; MAGI and filing status; appealing IRMAA due to what SSA considers life-changing events, and more. See: IRMAA Calculator, About section for details.

Sources:

Medicare (https://www.medicare.gov/)
Social Security Administration (SSA) (https://www.ssa.gov/)

Related Calculators

Definitions and Abbreviations

IRMAA is the acronym for Income-Related Monthly Adjustment Amount, enacted in 2003 through the Medicare Modernization Act. Under IRMAA, those deemed to be higher income earners in a given premium year, pay more (via surcharges) for Part B and Part D, thereby receiving less subsidization.
SSA determines if a medicare beneficiary will pay the surcharge in a given premium year, using the IRMAA sliding scale tables for the MAGI and tax filing information provided to them by the IRS.
MAGI is the acronym for Modified Adjusted Gross Income. It is calculated using the tax return for 2 years prior to the premium year (or, according to SSA, a maximum of 3 years back if 2 years is not available).

Per SSA, MAGI is calculated by adding two lines from IRS Tax Form 1040:
- Line 11: Adjusted Gross Income, plus (+)
- Line 2A: Tax-exempt interest income
SSA - Social Security Administration of the United States.
IRS - Internal Revenue Service of the United States.

When determining if IRMAA is applicable to a Medicare beneficiary, SSA gets tax information from the IRS for two years prior to the premium year.
CMS - Centers for Medicare and Medicaid Services of the United States.
Tax Filing Status - When calculating IRMAA, there are three tax filing statuses, each corresponding to 3 distinct sets of IRMAA sliding scale tables:
1. Single, head-of-household, or qualifying surviving spouse with dependent child
2. Married filing Jointly
3. Married filing Separately
On this calculator, when selecting tax filing status, Single is used to represent: Single, Head-of household, or Qualifying surviving spouse with dependent child.

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 has no provision for Medicare Part A. This calculator is based on Medicare and IRMAA in the United States, and is not applicable to any other country.