Obama picks Colvin to head Social Security agency

President Barack Obama is choosing the acting commissioner at the Social Security Administration to officially fill the job, amid looming financial challenges.

The White House says Obama will nominate Carolyn Watts Colvin. Colvin's been the deputy commissioner for three and a half years. She's been acting head of the agency since former commissioner Michael Astrue stepped down in February at the end of his six-year term.

Colvin's nomination comes at a critical time for the massive retirement and disability program, with trustees saying trust funds will run dry in 2033. That would leave only enough revenue to pay about 75 percent of benefits. Already the program is paying out more in benefits than it collects in payroll taxes.