An Option Gain Can Enter Medicare's Income Record Two Years Later

A fictional investor pays $600 for a call and sells it for $1,800. The $1,200 gain reaches the tax record after the option position has closed. For someone covered by US Medicare, that record can matter again when a later year's premiums are determined.

A realised option capital gain can increase the adjusted gross income used for Medicare's income-related premium calculation, subject to the investor's complete tax-return facts. The relevant income definition and the year attached to it deserve separate checks. A profitable closing sale alone establishes neither a premium surcharge nor its amount.

This discussion concerns ordinary personal investing in a taxable US brokerage account and Medicare Part B or Part D income-related monthly adjustment amounts, known as IRMAA. It does not calculate a reader's tax, premiums, eligibility or benefit payments. The example follows a completed closing sale, not an unrealised account mark. Retirement accounts, employee options, dealer or business treatment, trader elections, section 1256 contracts, straddles and special tax adjustments are outside the example. Australian Medicare is a different system. This is general education, not personal investment, retirement, legal or tax advice.

Medicare has a specific income measure

The Social Security Administration's Medicare premium guidance explains that higher-income beneficiaries can pay additional amounts for Part B, Part D or both, depending on their coverage. SSA uses tax information supplied by the IRS and sends a determination explaining the adjustment.

For this calculation, SSA defines modified adjusted gross income, or MAGI, as adjusted gross income plus tax-exempt interest. The IRS definition of adjusted gross income includes capital gains among the income sources considered, with applicable adjustments. AGI is calculated before the standard or itemised deduction.

The calculation therefore needs the tax-return result, including relevant netting and adjustments. Copying an option's gross sale receipt into MAGI would overstate the gain in the example below. Treating every dollar left in a brokerage account as outside the calculation would also use the wrong record.

Other income tests have their own definitions. OMP's IRA contribution-room article examines taxable compensation. That definition cannot be substituted for Medicare MAGI. The IRA required-distribution article follows a separate account-withdrawal record.

Follow the gain into the annual record

Assume a fictional US personal investor buys one fully paid, unadjusted American-style Alder Co. $50 equity call covering 100 shares for $6 per share. The investor later sells the same contract to close for $18 per share, before expiration, during tax year 2026. There is no exercise, assignment or continuing stock position. All amounts are US dollars; the company, prices and transactions are invented.

The purchase costs 100 × $6 = $600. The closing sale produces 100 × $18 = $1,800. Subtracting the purchase cost leaves a $1,200 gain. The fictional $1,800 closing receipt contains a $1,200 gain and $600 of returned cost; the example predicts neither a surcharge nor an appropriate retirement trade.

IRS Publication 550 classifies a gain from selling an option as capital gain when the underlying property is, or would be, a capital asset in the holder's hands. That supplies the narrow ordinary-investor classification used here. The publication available at preparation is the 2025 edition; its developments page and the applicable tax-year rules require checking before use.

Now stipulate that the investor's annual AGI, before adding this gain, is $103,000, with $4,000 of tax-exempt interest. Assume no capital-loss carryforwards, offsetting capital transactions or other interactions, and that the gain increases AGI dollar for dollar. The examples exclude transaction charges, bid-ask costs, financing and currency changes. These simplifying facts are not a completed return calculation.

The annual income records are:

• Before the gain, $103,000 AGI plus $4,000 tax-exempt interest gives $107,000 Medicare MAGI.
• After the gain, $104,200 AGI plus the unchanged $4,000 gives $108,200 Medicare MAGI.
• The increase is $1,200. Adding the entire $1,800 receipt instead would produce $108,800, overstating the stipulated result by $600.

None of those figures is an official threshold. They show how the record changes. Whether $108,200 attracts an adjustment requires the applicable premium year's rules, filing status, coverage and SSA determination. An income increase can leave someone within the same premium band; it can also cross a boundary. No surcharge or tax payable is calculated here.

The premium year usually comes later

Medicare IRMAA generally uses tax information from two years before the premium year; a 2026 gain does not by itself establish an immediate 2026 premium change.

SSA's current explanation says 2026 determinations generally use tax year 2024 information. Its operational guidance permits information no more than three years old when the more recent return is unavailable. A current brokerage balance and the income year on an SSA notice can therefore describe different periods.

If the ordinary two-year relationship and current framework continue, tax year 2026 would generally be the reference year for 2028 premiums. That is a conditional calendar illustration, not a forecast of 2028 thresholds, premium rates or the return SSA will actually use. Today's premium table cannot supply those future figures.

A one-off gain also supplies no promise that an adjustment will be waived when later trading income falls. SSA's request-to-lower-IRMAA guidance describes relief requests involving qualifying life-changing events and amended returns. The agency must assess the actual facts and evidence. The example makes no relief or appeal determination.

Four portfolio limits still apply

Liquidity

The $18 closing price is stipulated, not an executable quote. The OIC bid-and-ask guide explains slippage and the possibility that a limit order remains unfilled. OMP's liquidity guide follows the same execution distinction. Money needed for healthcare or a dated household bill may be unsuitable for an option that cannot be sold at the assumed price.

Concentration

The call depends on one company. Existing shares and funds can add exposure to that issuer or sector, as FINRA's concentration guidance explains. A later premium concern cannot establish the right holding size or justify leaving an unsuitable concentrated position open.

Time horizon

The call's expiration and Medicare's income lookback follow different clocks. The OIC long-call guide explains the option's finite life and possible loss of the full premium. A hoped-for later price or a preferred tax year does not extend that life. The profitable sale in this illustration is no basis for expecting the next contract to fund retirement spending.

Funding suitability

The investor must be able to lose the $600 premium without jeopardising essential spending. A sale to close ends this fictional option holding. Exercising the stipulated $50 call instead would require a separate 100 × $50 = $5,000 share purchase and introduce continuing stock exposure. The OIC exercise FAQ explains funding and broker procedures. The long holder exercises; assignment concerns the short writer. Broker cutoffs, automatic exercise handling, charges and account permissions require an actual-contract check. The premium-loss limit does not cap a later stock holding's loss.

Match the notice to the return

Keep the option's cost, closing proceeds, realised result and charges alongside the tax return's AGI and tax-exempt interest. Record the income year and premium year separately. A qualified US tax professional can assess the return; SSA can explain the income year and determination on its notice. Those records are the useful starting point before drawing a conclusion from a profitable option sale.

Sources and scope

Sources were accessed on 29 October 2026, Australia/Brisbane. The example is fictional author arithmetic, not a live price, calibrated valuation, forecast, customer result or complete tax return. The $1,200 AGI increase is conditional on the stated simplified facts. No premium threshold, tax rate, tax bill or future surcharge is modelled.

Options involve risk and are not suitable for all investors. A long call can lose its entire premium; exercise can create a separately funded stock position. Read the current options disclosure document supplied by the broker and the applicable contract and account requirements before trading. This discussion does not replace those documents or a professional assessment.

Options Matrix Pro publishes this education and has a commercial interest in its options-analysis platform. It cannot determine personal Medicare premiums, tax treatment or a suitable retirement allocation. The OMP disclaimer applies.