“We’ve paid more than the guaranteed payouts to our fixed annuity holders every year for more than half a century,” Mr. Peterson said. “We’ve paid $394 billion in benefits to retired participants since 1918. Since our founding, our retired participants have never missed a payout from us — through depressions, wars and natural disasters.”

According to interviews with 10 former employees, TIAA management assigned outsize sales quotas to its representatives and directed them to meet the quotas by playing up customers’ fears of not having enough money in retirement and other “pain points.”

These allegations are echoed in a confidential whistle-blower complaint filed against the company with the Securities and Exchange Commission and obtained by The New York Times. The complaint, which is pending, contends that TIAA began conducting a fraudulent scheme in 2011 to convert “unsuspecting retirement plan clients from low-fee, self-managed accounts to TIAA-CREF-managed accounts” that were more costly. Advisers were pushed to sell proprietary mutual funds to clients as well, the complaint says. The more complex a product, the more an employee earned selling it.

Those who questioned management’s directives, the complaint says, were “processed out” of TIAA.

Under the legal standard applied to retirement accounts, these plans must be run solely in the interests of participants and beneficiaries. Fiduciaries are barred from engaging in transactions in the plan that would benefit them or other service providers like TIAA.

Clients must also be told of conflicts. Sales representatives who do not make this clear would violate the rules.

The former TIAA employees spoke on condition of anonymity for fear of retribution. TIAA makes employees sign an unusual agreement when they are hired stating that they will not make disparaging public comments about the company. The agreement, reviewed by The Times, gives TIAA the right to go to court to force compliance with its terms.

TIAA’s claims that it is more honorable than its competitors may have been true decades ago, but they no longer are, the former employees said.