Sent on Tuesday, the letter was made public hours before President Obama will unveil his budget for 2014.
The proposal would turn off the sequester budget cuts, set to eliminate nearly 7 percent of federal spending on scientific research this year, according to advocates.
The Nobel laureates did not mention sequestration or endorse Obama's plan, but said lawmakers should remember the younger generation of scientists that will be disadvantaged by steep cuts.
"We urge you, even in these financially troubled times, to keep the budgets of the agencies that support science at a level that will keep the pipeline full of the younger generation upon whom our economic vitality will rest in future years," the group wrote.
The letter was organized and circulated by the Federation of American Scientists.