The idea of investing in every baby at birth has spilled into Congress, where an unusual alliance of conservative and liberal lawmakers introduced legislation in April to create KIDS Accounts.

Under the House and Senate bills, the government would give $500 to every baby with a Social Security number, and twice that amount to those in families with less than the median income.

Contributions to the tax-free accounts from relatives or friends would be matched, up to $1,000 in the Senate version and $2,000 in the House bill. The accounts would be held in a fund overseen by a board similar to that for the Thrift Savings Plan for federal workers and could not be touched before the age of 18. After that, people could shift them to private investments, if they preferred, but could only use the money before retirement to pay for college or a first house. People would be required to repay their initial $500, including by doing volunteer work.

According to congressional budget estimates, the Senate bill would cost about $37 billion over its first decade, the House version about $70 billion.

Sen. Rick Santorum (Pa.), an architect of the legislation and chairman of the Senate Republican Conference, praised the expenditure as "a private-sector approach" that he said "fits into the idea of giving people incentives to create wealth." Sen. Charles E. Schumer (D-N.Y.), one of Congress's leading liberal voices, called the program an "education" device that offers "a head start for your piggy bank."