People born after 1959 now have to wait till age 67 to collect full benefits.
"If you're on the program now or anywhere near eligibility, you shouldn't have your benefits impacted," Pawlenty told The Miami Herald during a campaign stop.
"But if you're in the next generation, we're telling you now, with several decades of warning, we're going to gradually raise the retirement age over time. If you're lower income or middle income, you should still get your cost-of-living adjustment. But in the future, if you're real wealthy, we're going to have to slow that down or take it away."
The Social Security Administration estimated in May that under current law the 76-year-old social-insurance program's trust funds would be exhausted in 25 years and need $6.5 trillion in additional money over 75 years -- roughly $87 billion a year -- to pay all scheduled benefits.
In addition, President Barack Obama and Republicans are discussing changes in the formula for Social Security cost-of-living adjustments long sought by economists.
Pawlenty, who is trailing in the polls and lost his top campaign policy adviser this week, also told the newspaper the Department of Homeland Security's E-Verify federal database to ferret out illegal immigrants should not be mandatory for private employers.
His position conflicts with a Republican-sponsored bill that would force all employers to verify the legal immigration status of their workers.
"We should say to private employers, if you knowingly hire illegal immigrants, there's going to be a consequence," he told the newspaper. "I underline the word 'knowingly.' And you make available a system like E-Verify. I don't know that you need to require them to use it."
E-Verify supporters argue the free electronic system, mandatory for most federal contractors but voluntary for other employers, would eliminate any doubt about workers' legal status.
Pawlenty would not say if he thought human activities had anything to do with climate change.
"Well, there's definitely climate change," he said. "The more interesting question is how much is a result of natural causes and how much, if any, is attributable to human behavior. And that's what the scientific dispute is about."
The scientific consensus is that climate change is in large part caused by human activities and may to some extent be irreversible.
And Pawlenty said he saw no inconsistency when he bashed Obama's stimulus plan as governor in 2009 yet took the money at the same time.
"If the federal government is dumb enough to give it to us, we'll be smart enough to take it," he said.