This year the company expects more than 170 of its offices to participate and serve an estimated 16,000 senior citizens.
Mason has been in charge of the program at his office for about 10 years.
Mason said the Franklin County Office on Aging, which runs seven senior centers, selects the seniors who will make the calls.
"This is not open to everyone over the age of 65. It's for people who would normally find making a long distance call a difficult expense," Mason said.
"We do business by phone. We have about 17 phones in this office," he said.
It costs his office more than $2,000 for the calls, he said. AT&T gives Merrill Lynch a break on the cost, he said.
"We used to get a lot of World War II-era war brides in this office who called their families overseas, but many of them have been passing on or moving into nursing homes," Mason said. "You could stand in the middle of the office and hear conversations in German, Russian, French, Chinese - it was like the United Nations around here."
About 10 employees from the local office volunteer each year to help the seniors with their calls.
They also will serve coffee, punch and cookies to the 35 seniors expected to come in to make calls this morning, he said.