Washington ? The Supreme Court gave bankrupt Americans another layer of financial protection Monday, ruling that creditors cannot seize their Individual Retirement Accounts.

The unanimous decision shields a nest egg relied upon by millions of people.

The justices said IRAs should join pensions, 401(k)s, Social Security and other benefits tied to age, illness or disability that are afforded protection under federal bankruptcy law.

Justice Clarence Thomas, writing for the court, said a bankrupt Arkansas couple was entitled to keep more than $55,000 in retirement savings from creditors. He reasoned that IRAs are benefits tied to a person’s age under the federal statute because a tax penalty is imposed if a person makes withdrawals before age 60.

“That penalty erects a substantial barrier to early withdrawal,” Thomas wrote. “Funds in a typical savings account, by contrast, can be withdrawn without age-based penalty.”

The ruling affects 16 states and the District of Columbia, which do not have their own state laws protecting IRAs. The remaining 34, including Kansas, have separate state laws.

IRAs let most investors contribute up to $4,000 annually to a fund that grows tax-free until withdrawals. It is the retirement plan typically used by workers between jobs, according to AARP, the advocacy group for people older than 50.