"Do something with the solvency of Social Security, which is the biggest elephant in all the rooms," said Simpson, retired U.S. senator from Wyoming and GOP co-chair of former President Barack Obama's bipartisan debt commission. Erskine Bowles, former chief of staff during Bill Clinton's presidency, was the Democratic co-chair.
Among the ways to shore up Social Security would be to "change the retirement age to 68 by the year 2050," Simpson said on "Squawk on the Street."
Workers who are 62 in 2017 can retire with full Social Security benefits when they're 66 and two months. The full retirement age is increasing gradually to age 67.
Raising the retirement age was a key debt-reducing component of the 2010 Bowles-Simpson plan, which fell short of the votes from the bipartisan panel needed to recommend the framework to Congress.
"You can't do any of that [or] AARP will tear your underwear from your body. They don't care about anybody under 50," Simpson said. "That's a monstrous organization."
An AARP rep said, "AARP cares about Social Security for current and future generations of American families."
Simpson's appearance on CNBC came after last week's annual saber rattling over increasing the debt limit. President Donald Trump on Thursday accused Republican leaders in the Senate and the House of botching efforts to avoid an unprecedented default on the national debt.
I requested that Mitch M & Paul R tie the Debt Ceiling legislation into the popular V.A. Bill (which just passed) for easy approval. They…
...didn't do it so now we have a big deal with Dems holding them up (as usual) on Debt Ceiling approval. Could have been so easy-now a mess!
Every year, hardline conservatives play a game of chicken with paying the interest on the national debt, which is approaching $20 trillion. They threaten a default, trying to get spending cuts.
A 2011 standoff between Republicans and the Obama administration was not resolved until the eleventh hour and prompted Standard & Poor's to impose the first-ever downgrade of America's credit rating.
Simpson, who spent decades on Capitol Hill, said the debt-ceiling fight is a "horrible dream." While an advocate of spending cuts, he said that using the full faith and credit of the United States as a bargaining chip is the wrong way to go about it. "You've already blown the money."
Politicians want it both ways, he added — they say they want to cut spending and they say that it's possible without touching entitlements. Simpson said anybody who says that's possible is a "lying sack of … " He did not finish the sentence.
The Treasury Department has said the debt ceiling needs to be raised by Sept. 29 to avoid potential default on government obligations including Social Security and interest payments.
— Associated Press contributed to this report.