For decades, career civil servants at the White House budget office have held a quiet but essential role in doling out trillions of dollars in the federal budget. Throughout the year, they parceled out money appropriated by Congress to agencies meant to spend it.

Today that job is held by loyalists to President Trump who have turned a routine task of financial management into a potent policymaking tool — and one that has set the White House on a collision course with Congress over its constitutional power of the purse.

In more than 100 cases this year, Office of Management and Budget officials who sign off on funds for federal agencies have attached unusual conditions to the money, including requirements that funds meant to reflect Congress’s priorities be spent only if they align with the president’s views. The moves lay the groundwork for the Trump administration to choke off billions of dollars budgeted by Congress for education, health, housing and research programs.

In some cases, the administration has clearly blocked funding for specific programs. In others, the threat lurks in footnotes tucked in detailed budget logs that congressional appropriators are racing to decipher as their conflict with the budget office grows.

The administration’s efforts to tighten control over spending are apparent in a trove of newly released records, which the White House budget director Russell T. Vought had pulled from public view in March and fought in court to keep secret. The administration only began to publish those documents earlier this month under court order.

A New York Times analysis of thousands of these records posted online through Friday morning shows that the White House has targeted spending at three agencies in particular: the Departments of Health and Human Services; State; and Education. The administration has sought to restrict funding for programs that help families reduce their home energy bills, mothers buy food for young children and laid-off workers find training.