Raleigh, N.C. — More than 56 million people who collect Social Security will get a slight raise next year of 1.7 percent. Retired workers, who collect on average about $1,240 a month, will see an increase of about $21 a month.

The increase, which starts in January, is tied to a measure of inflation released Tuesday. It shows that inflation has been relatively low over the past year, despite the recent surge in gas prices, resulting in one of the smallest increases in Social Security payments since automatic adjustments were adopted in 1975.

About 8 million people who receive Supplemental Security Income will also receive the cost-of-living adjustment, or COLA, meaning the announcement will affect about 1 in 5 U.S. residents. Social Security also provides benefits to millions of disabled workers, spouses, widows, widowers and children.

One of the affected workers is Jean Robertson, a 73-year-old Raleigh resident who retired as a mental health worker in Philadelphia 12 years ago due to a two-time battle with cancer. She lives on $920 a month from Social Security and says she is dealing with the greatest financial challenge she has ever faced.

“It’s very difficult lately. (The) price of gas and the food is going up,” she said. “I limit my driving because of the price of gas.”

Roberson says she doesn't like to owe people money and refuses to put off paying bills or to live on credit.

“A lot of times I don’t have any paper money in my pocket, but I don’t have anybody ringing my doorbell and beating up my telephone,” she said.

Roberson says she is grateful for an increase in Social Security benefits next year, even at 1.7 percent. However, she says it's still tough to make ends meet.

“It doesn’t even out at all,” she said.

North Carolina State University professor Robert Clark has studied issues involving Social Security and says he wasn't surprised by the amount of the increase.

Increases are determined by a formula involving the Consumer Price Index for Urban Wage Earners and Clerical Workers, a broad measure of consumer prices generated by the Bureau of Labor Statistics. It measures price changes for food, housing, clothing, transportation, energy, medical care, recreation and education.

“By statute, Social Security benefits are increased at the same rate as (the) increase in consumer prices,” said Clark, who works in N.C. State’s College of Management. “So, no congressman votes on this. The president doesn’t have to sign anything on it. This is an automatic increase based on specific legislation.”

Since 1975, the annual COLA has averaged 4.2 percent. Only five times has it been below 2 percent, including the two times it was zero in 2009 and 2010. Before 1975, it took an act of Congress to increase Social Security payments.