She Bought an Annuity at 68 for the Guaranteed $2,000 a Month. It Made 85% of Her Social Security Taxable, Then Made Every Roth Conversion After It Cost More

A guaranteed check for life, arriving on the first of every month, solves a fear that keeps a lot of retirees up at night: outliving the money. That fear is real, and the appeal is legitimate. In the illustrative scenario at the center of this piece, a 68-year-old woman handed an insurer a lump sum and started receiving $2,000 a month for life. The annuity did what it said it would do. The checks arrived, but the damage happened elsewhere entirely, in three places on her tax return she hadn’t been asked to review before she signed.

First Surprise: Social Security Quietly Became Taxable

Remember that Social Security isn’t taxed like wages at a flat rate applied to the benefit. Whether any of the benefit is taxable depends on a separate measure that combines other income with a portion of the benefit itself. As that measure rises, a larger share of the benefit gets pulled into the taxable column, up to a statutory ceiling of 85%. The thresholds that trigger this were written decades ago and are not indexed to inflation the way the regular brackets are, so more retirees cross them every year without changing anything about their own behavior.

Annuity income didn’t simply get taxed on its own. It raised that underlying measure and dragged a largely untaxed benefit into taxability. One decision produced two tax hits: the annuity dollars themselves, and a chunk of Social Security that had been sitting quietly outside the return the year before. The 3.1% COLA tracking for 2027 does not fix this. A bigger benefit only means more of a bigger number becomes taxable once the floor has been raised.

Second Surprise: Every Roth Conversion Afterward Costs More

This is the part almost nobody models before signing an annuity contract, and it is the heart of the story. A Roth conversion is voluntary. You move money from a pre-tax account into a Roth, pay ordinary income tax on the converted amount now, and get tax-free growth and withdrawals forever after. The cost of any conversion depends entirely on the tax rate the converted dollars land in, and that rate depends on how much other income is already stacked underneath them.

By adding a permanent guaranteed income stream at the bottom of the stack, the annuity raised the floor under every future conversion for the rest of her life. A conversion that would have landed in a low rate before now stacks on top of the annuity and lands in a higher one. Worse, that same conversion drags additional Social Security into taxability, compounding the bill. The window between retirement and the start of mandatory withdrawals is generally the cheapest conversion runway a retiree will ever have (we sized up that gap between the last paycheck and the first RMD in a free Roth guide here: The Roth Window). Filling that window with a permanent floor of guaranteed income spends it.

Third Surprise: A Medicare Bill Arrives Two Years Late

Higher income can also lift Medicare premiums through an income-related monthly adjustment. The key detail is timing: the surcharge is assessed on income from two years earlier, so the premium increase arrives long after the annuity decision that produced it, at a moment when it feels unrelated to anything she recently chose. The check she signed at 68 shows up as a higher Medicare bill at 70, and it can keep showing up.

What She Should Have Asked Before Signing

Three questions would have changed the outcome. First, would delaying the annuity purchase by even a few years have preserved the low-income window for conversions? Timing is the real lever here. Second, what type of account was funding the annuity? Payments from an annuity bought inside a tax-deferred account are generally ordinary income, while payments from one bought with after-tax savings carry a different tax character, and that difference interacts with everything above.

Third, and most importantly, did anyone model the entire return, or only the product? The failure here was evaluating the annuity on its own merits in isolation. A fixed-income alternative such as a laddered CD, currently averaging 1.71% nationally with top online banks paying multiples of that, would not have solved the longevity problem, but it would have kept the conversion window open.

Verdict: Order of Operations Beats Product Choice

There is a definite argument to be made that guaranteed income is worth paying for. However, the order of operations matters more than the product, and this individual will pay the cost of getting it wrong every year for the rest of her life. The annuity might have kept its promise, but the rest of the tax return is paying the price.

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