To dramatize Ronald Reagan's determination to transfer federal programs -- and revenue -- to the states, the president-elect's policy-planners are toying with a plan under which a certain portion of each citizen's federal income tax would be automatically earmarked for delivery to his or her state.

The Reagan people say the system might involve a line at the bottom of the standard income tax return. Form 1040, directing the taxpayer to split any taxes due into two checks, one to be sent to his state capital and one to Washington.

None of the numerous details involved in such a program have been developed, but the idea has a basic appeal to Reaganites, because the shift of authority from Washington to the states is central to the president-elect's blueprint for change. The "earmarking" system would be a way to get across to every taxpayer that Reagan meant what he said about decentralizing some government functions.

The function Reagan has promised most often to move out of Washington is aid to the poor -- the programs generally described as "welfare." Throughout his campaign this year, Reagan cited the welfare program he established when he was governor of California as proof that state and local governments can handle this function more efficiently than the federal government.

"His success in the welfare field is why he thinks many things can be moved back to the states," Robert Carleson, who was state welfare director under Gov. Reagan, said in an interview earlier this year. Carleson is head of the Reagan transition team at the Department of Health and Human Services, the agency that oversees most federal welfare programs. He is considered the leading candidate for secretary of HHS.

Carleson was the architect of the Dole-Long bill, a legislative proposal that incorporates Reagan's ideas for tranferring welfare to the states. The bill would end the current system of open-ended matching grants for state welfare systems and instead provide "block grants" of a specific sum. Over time, the block grants would be reduced, as would federal taxes, leaving it to the states to tax the extra revenue and, eventually, fund welfare on their own.