WASHINGTON (AP) _ President Bush's budget for health and social programs falls short, even though it proposes some new and expanded programs, say advocates for the low- income, elderly and children.

The administration, in unveiling its proposal Monday for next fiscal year, put the spotlight on hefty increases in child health programs and cancer screenings.

But, said Bob Greenstein of the Center on Budget and Policy Priorities, ''in many cases, the funds to expand one low-income program are funded through a cut in another low-income program.''

John Friel, executive director of the Coalition for Health Funding, had the same complaint and pointed to one of the Health and Human Services Department's pet proposals, a $171 million project to help high-risk, pregnant women get prenatal and infant care services.

''While laudable in concept to address the appalling problem of infant mortality, removing needed money from (other programs) ... is shortsighted,'' said Friel, whose coalition includes more than 40 national organizations.

Sen. Lloyd Bentsen, D-Texas, chairman of the Senate Finance Committee, said Bush's plan to find $25 billion in Medicare savings over the next five years - in addition to $42 billion agreed upon by Bush and Congress - ''is simply unacceptable.''

The savings would result mostly from holding down growth in payments to doctors, hospitals and laboratories.

The plan also would triple Part B Medicare premiums for individuals who earn more than $125,000 or couples who earn more than $150,000. About half a million people would be affected, officials said.

This would make an important change in the program that covers doctors' bills. Currently, those who choose to participate in that part of Medicare pay $32 a month - regardless of their income.

HHS Secretary Louis Sullivan said that because that program is expected to increase by 13 percent in the coming year, ''I believe that it is fair to make wealthier individuals share more of the burden.''

He said this would save about $41 million next year and $1.2 billion over five years, but Greenstein said these figures ''represent a very small fraction of the multibillion-dollar annual gain that people in these income brackets would receive from a capital gains tax cut'' that Bush also proposed.

This proposal would be a step toward basing Medicare benefits on income. Many have resisted this path, saying Medicare gets its popularity from being an entitlement program, rather than a welfare program.

Recent efforts to have the elderly pay for more of their health care have failed. Senior citizens' complaints about the financing of a catastrophic health care program persuaded Congress to repeal the program less than a year after it was enacted.

With the administration's proposed changes, Medicare spending next fiscal year would rise from the current $104 billion to $113 billion - an increase of about 8 percent. With no changes, the increase would be more than 11 percent.

Budget authority for AIDS spending on research and education would go from the current $1.88 billion to $1.95 billion, an increase of 3 percent, which prompted AIDS activists to accuse Bush of abandoning AIDS.

''This proposal is a slap in the face to millions of Americans on the front lines, the families and volunteers in the war against AIDS,'' said Tim McFeeley, executive director of the Human Rights Campaign Fund.

Screening programs for breast and cervical cancer would get a hefty increase, up 71 percent next fiscal year to $50 million.

Funding for the Head Start pre-school program for disadvantaged children would increase by $100 million to $2 billion. Asked why such a small increase is being proposed after two successive increases of $750 million, HHS budget chief Kevin Moley said, ''There is a need for a breathing spell for the infrastructure out there to absorb the money.''

The Low Income Home Energy Assistance Program would see its funding cut by more than a third, from $1.4 billion this year to $925 million next fiscal year. Sullivan said the program would focus its efforts in the Northeastern states, which rely heavily on heating oil.