The home secretary has declined to specify how much scrapping her plan to make foreign care workers already in the UK wait longer to qualify for permanent settlement will cost.
Shabana Mahmood had originally proposed doubling the wait from five years to 10 for most migrants, with some facing a 15-year wait, which the Home Office suggested could save £10bn.
Under revised plans, some foreign care workers will wait five years and others will be able to seek a five-year extension, in what the Tories have called a "U-turn".
While not detailing the cost of the revised plans, Mahmood said the state would still save "billions" because workers in other sectors would have to wait longer.
In March, the Home Office said, external the net lifetime cost of care workers and their adult dependants expected to settle between 2026 and 2030 was estimated at £10 billion.
Mahmood announced plans to delay settlements last November in response to concerns over the number of people approaching eligibility in the wake of record post-Brexit net migration figures under the previous Tory government - dubbed the "Boriswave" by critics.
Following a backlash from several Labour MPs, Mahmood announced on Monday that care workers who arrived in the UK before May 2025 and earned at least £25,000 a year would continue to qualify after five years, alongside some other groups.
Indefinite leave to remain (ILR), also known as settlement, gives a person the right to live, work and study in the UK for as long as they like and apply for benefits if they are eligible. They can also use it to apply for British citizenship.
Asked about the cost of her revised plans, the home secretary told BBC Radio 4's Today programme the detailed costs would be published when her department puts the changes before Parliament.
She said the changes overall represented "savings in the billions" to the Department of Work and Pensions in people not claiming benefits.
"The reason for that is the cohort that was most likely to fall upon the state is that cohort of care workers not doing care work at the moment - if they'd settled at five years, many more of those would have gone on to claim benefits.
"That will now not happen because they will not be settling at five years - those individuals get a second chance to make that contribution that they originally came to make," she told Today.
The Conservatives said her "U-turn" will cost the state billions of pounds.
Mahmood had faced criticism within the Labour Party for proposing to change the rules for migrant workers already in the UK.
Housing Secretary Angela Rayner had said it amounted to "chang[ing] the goalposts", while several MPs described the retrospective approach as "un-British" and warned it could worsen the UK's skills shortage, particularly in the care sector.
Shadow home secretary Chris Philp said opposition from Mahmood's fellow ministers and the "Labour open-borders left" had resulted in the changes.
Reform UK leader Nigel Farage said Mahmood had "talked a big game on immigration but has U-turned at the first sign of trouble".
Liberal Democrat home affairs spokesman Max Wilkinson said the government's reforms were "unravelling", while calling for an "informed national discussion" on immigration.
Green Party MP Siân Berry said Mahmood had provided a "new obstacle course of hoops and barriers" for migrants living in the UK.
