WASHINGTON -- Timothy Geithner didn't pay Social Security and Medicare taxes for several years while he worked for the International Monetary Fund, and he employed an immigrant housekeeper who briefly lacked proper work papers.

Those issues, and a series of other tax matters, scuttled a tentatively scheduled confirmation hearing Tuesday for Mr. Geithner as Treasury secretary, Senate Finance Committee aides said. The tax matters were instead the subject of a closed-door meeting between the nominee, currently president of the...