For retirees who have recently elected to take Social Security benefits, this could be the first time they see a "real increase" in their monthly checks, Joe Elsasser, president of Covisum, a provider of Social Security timing software, previously told CNBC.
For those who are collecting an average Social Security benefit of about $1,400, the 2019 cost-of-living adjustment will amount to an extra $39 per month.
The Medicare Part B premiums for next year have not been announced yet. Estimates peg those premiums at $135.50 in 2019 for those with incomes below $85,000.
In the past the boost from the Social Security cost-of-living adjustment has been eaten up for many by higher Medicare premiums.
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That is unlikely to happen to as many people this year as it did in 2018, according to Mary Johnson, Social Security and Medicare policy analyst at the Senior Citizens League.
Individuals with Social Security benefits from around $600 to $634 could be most affected.
"That group will likely see their Part B premium take up their entire COLA in 2019," Johnson said.
The number of Social Security beneficiaries with benefits in that range is about 5 million, according to Johnson, though not all of those individuals are necessarily enrolled in Medicare.