Those holding their breath for a substantial bump in 2017’s cost-of-living-adjustment to Social Security benefits are most likely doing so in vain.

On October 18, the U.S. Department of Labor's Bureau of Labor Statistics will officially announce the Social Security Cost-of-Living Adjustment rate for 2017, which is derived from averaging the July, August, and September inflation numbers from the Consumer Price Index for Urban Wage Earners and Clerical Workers, or the CPI-W index.

From there, actuaries average this year’s inflation increase with the previous Cost-of-Living Adjustment, which was made in the third quarter of 2014. There was no COLA in 2015.

If this year’s three-month CPI-W gauge is higher than the third quarter’s in 2014, then an increase in the COLA is warranted.

Earlier this year, the Social Security Administration released its own predictions for the 2017 COLA, cautioning that any increase should be expected to be slight. In its 2016 Trustees Report, SSA estimated that a 0.2 percent COLA increase is most likely.

In the third quarter of 2014, the average CPI-W registered at 234.252. Data from July and August of this year, which has already been released, showed marginal increases from the 2014 baseline number—234.789 for July, and 234.909 for August.

Since 1975, COLA increases have been issued in all but three years — 2009, 2010 and 2015. In that period, the increase dropped 22 times from the previous year, but on average, the COLA has increased 3.88 percent since 1975, and 2.27 percent since 2000.

If SSA’s predicted 2017 increase of 0.2 percent holds true, it would mark the lowest rate increase on record, not accounting for the three years when there was no increase.

Changes to defined contribution and defined benefit plan limits

Inflation data from the third quarter of this year will also affect the amounts on retirement benefit plan limits.

Those limits are calculated using inflation measurements that are different from how the Social Security Administration handles COLA adjustments. The Consumer Price Index for All Urban Consumers, or CPI-U, is used to establish COLA increases for defined benefit and defined contribution plans, not the CPI-W used to set COLA increases for Social Security.

By and large, limits to retirement plans will remain unchanged in 2017, with a couple of exceptions, according to Marge Martin, a principal and actuary for Buck Consultants professional services group, a division of Xerox HR Services.

The $18,000 deferral limit on 401(k) and other defined contribution plans will likely not change, unless inflation numbers for September of 2016 show a 2.7 increase, a rate that would far outpace the number expected by the consensus of the country’s economists, Martin said in an interview.

But if the CPI-U numbers in September are equal to the small increase seen in August, some retirement funding thresholds will marginally change.

In a blog post, Martin predicted that the defined contribution annual addition threshold will increase to $54,000, from $53,000 this year. The annual addition is the combination of employer and employee contributions, and forfeitures, or benefits an employee is not fully vested in.

Also, the maximum pension payout in a defined benefit plan is expected to increase from $210,000 to $215,000, according to Martin’s analysis.

And she predicts the compensation limit, which is the maximum salary a defined benefit plan can use to calculate pension benefits, will increase from $265,000 to $270,000. 

Medicare premiums expected to jump more than 22 percent

The 0.2 percent predicted COLA increase on Social Security benefits amounts to a $2 increase in benefits for every $1,000. The average monthly Social Security benefit is $1,335.

For some seniors, the paltry COLA increase is compounded by the fact that the Medicare Board of Trustees is calling for Part B premiums to increase more than 22 percent, from about $121 a month in 2016 to about $149 a month in 2017. Those premiums are deducted from Social Security benefits.

Under Medicare’s "hold harmless" provision, most Americans, including the most vulnerable seniors, are protected from having their Social Security benefits reduced because of increases in Medicare premiums. The rule applies to all beneficiaries with household income of less than $85,000 a year for a single retiree, and $170,000 for a married couple.

Low inflation most affects Social Security recipients

Low inflation’s impact on COLA adjustments will affect those seniors that most rely on Social Security to fund retirement, compared to the effect on deferral and benefit limits for those saving for retirement, notes Martin.

“The benefits aren’t going up because the index says the cost of living isn’t either — but ask most seniors who are seeing their rent go up, and they’ll probably say the landlord isn’t relying on the CPI-W to base their increases,” said Martin.

“The low COLA increases by far have the most impact on Social Security beneficiaries,” she added. “For the limits on defined benefits, most people with a pension aren’t getting anything near the affected thresholds. And as for the limits on 401(k) deferrals, how many people are actually saving the maximum amount,” said Martin.