4 Social Security rules that are quietly shrinking your benefits

Many seniors end up living on just Social Security, or relying on those benefits for the bulk of their retirement income. But the monthly benefit you expect to collect may not be what you end up getting.

The reality is that Social Security is loaded with rules. Some can raise your benefits, such as the program's delayed retirement credits. But others can shrink your benefits, leaving you more reliant on savings and other income sources to stay afloat financially once your time in the workforce comes to an end.

Here are four Social Security rules that could be leaving you in the lurch, and why it's important to keep them on your radar.

1. The earnings test

Social Security recipients are allowed to work while collecting benefits. Once you reach full retirement age (FRA), you can earn any wage without having to worry about benefits being withheld.

But prior to FRA, you'll be subject to Social Security's earnings test. And exceeding the limit, which changes every year, could result in having benefits withheld temporarily.

Lawmakers, however, are fighting to change that. The recently introduced Senior Citizens' Freedom to Work Act seeks to repeal the Social Security earnings test. Proponents of the bill say that removing barriers for seniors to work helps strengthen the U.S. economy, all the while allowing retirees to supplement their Social Security income so they're able to better keep up with rising costs.

2. Taxation of benefits

In the wake of the One Big Beautiful Bill Act (OBBBA), the majority of people who collect Social Security are not liable for taxes on those benefits. That's because the bill introduced a temporary $6,000 senior tax deduction that allows most Social Security recipients to lower their income to the point where those taxes don't apply.

But the OBBBA did not do away with taxes on Social Security benefits. If lawmakers allow the new $6,000 senior deduction to expire after the 2028 tax year, which it's currently set to do, more retirees could owe taxes on their Social Security checks at that point.

Many feel that taxes on Social Security benefits are unfair because they're effectively double taxation. Retirees earn Social Security by working and paying taxes on their wages throughout their careers. To then have those benefits taxed feels like the IRS is coming after that money twice.

3. The provisional income formula

Not every Social Security recipient will owe taxes on their benefits once the $6,000 deduction expires. Having to pay those taxes hinges on provisional income, which is calculated as the total of adjusted gross income, tax-exempt interest income, and 50% of annual Social Security benefits.

The problem is that the provisional income thresholds at which taxes on benefits apply are very low. Single tax-filers face taxes on benefits once their provisional income reaches $25,000, while married couples filing jointly face taxes on Social Security once their provisional income reaches $32,000.

The problem is that the provisional income thresholds were established back in 1983. Since then, inflation has driven costs upward for seniors, making a provisional income of $25,000 for singles or $32,000 for couples minuscule.

Plus, while the provisional income thresholds have not increased since they were established decades ago, Social Security benefits have increased thanks to the program's annual cost-of-living adjustments (COLAs). Since those benefits themselves are part of the formula that determines whether those taxes apply, that disconnect could push more seniors into having to pay taxes on benefits in the coming years as benefits receive inflation boosts.

4. The COLA calculation

Social Security COLAs are meant to help benefits keep up with inflation. But the measure used to calculate them is flawed.

COLAs are based on changes to the Consumer Price Index for Urban Wage Earners and Clerical Workers (CPI-W). But the CPI-W measures the costs working Americans face, not retirees.

The nonpartisan Senior Citizens League says that between 2016 and 2026, Social Security benefits lost an estimated 13.7% of their buying power, largely due to insufficient COLAs. Advocates have pushed to calculate COLAs based on a more senior-specific index that could potentially lead to larger annual boosts.

Bottom line

Social Security may end up playing an important role in your retirement plan. It's important to understand the program's rules so you aren't surprised if your monthly benefits end up being smaller than expected.

Just as importantly, it's crucial to have a realistic expectation of what your monthly benefits might look like. The best way to get that information is to create a my Social Security account.

Once you do, you can access your most recent earnings statement to get an estimate of your monthly benefit at various ages. Having that information could help you better plan for your retirement, provided you understand how the rules above could have an impact on your monthly checks.