Elon Musk’s Department of Government Efficiency (Doge) – set up to cut US government spending – claims to have saved, on average, more than $10bn a week since President Trump entered office.

“We’re talking about almost $200bn and rising fast,” Trump told the BBC when talking about Mr Musk’s cost-cutting drive on 23 April.

Doge’s website says it is focusing on cancelling contracts, grants and leases put in place by previous administrations, as well as tackling fraud and reducing the government workforce.

BBC Verify has looked at the agency’s biggest claimed savings, examining the figures and speaking to experts.

Our analysis found that behind some of the large numbers, there is a lack of evidence to back them up.

In October, Mr Musk pledged to cut “at least $2 trillion” from the federal government budget. He subsequently halved this target and on 10 April talked about making savings of $150bn from “cutting fraud and waste” by the end of the next financial year in 2026.

The US federal budget for the last financial year was $6.75tn.

Doge publishes a running total of its estimated savings on its website – which stood at $160bn the last time the site was updated on 20 April.

However, less than 40% of this figure is broken down into individual savings.

We downloaded the data from the Doge website on 23 April and added up the total claimed savings from contracts, grants and leases.

Our analysis found only about half of these itemised savings had a link to a document or other form of evidence.

US media has also highlighted some accounting errors, including Doge mistakenly claiming to have saved $8bn from cancelling an immigration contract which in fact had a total value of $8m.

Doge says it is working to upload all receipts in a “digestible and transparent manner” and that, as of 20 April, it has posted receipts “representing around 30% of all total savings”. It also lists some receipts as being “unavailable for legal reasons”.

BBC Verify examined the four largest savings listed on the Doge website which had receipts attached.

The department claims these add up to $8.3bn, but after examining the evidence provided and speaking to people familiar with federal contracts, this figure appears to be overstated.

For three of the savings, Doge links to documents on the Federal Procurement Data System (FPDS). This is a database which records contracts given out by the US government.

The documents show a contract’s start and end date, the maximum amount the government has agreed to spend, and how much of that has been spent.

David Drabkin, a federal contracts expert who helped develop the FPDS database, said the maximum figure listed should be treated with caution.

“FPDS does not reflect the actual paid price until some period of time after the contract has been completed and the contract actions have been recorded,” he says.

“For example, when buying research and development into a vaccine no one really knows how much that’s going to cost – so when a price is set, it’s not a definite price but rather an upper limit.”

So if Doge counts the maximum figure, that can represent projected spending over a number of years, rather than a direct saving from the country’s yearly spending.

Doge’s largest listed individual saving is $2.9bn.

It comes from cancelling a contract – which started in 2023 under President Biden – for a facility in Texas to house up to 3,000 unaccompanied migrant children.

Doge appears to have taken the “total contract value” until 2028 – the end date listed – and subtracted the amount spent so far to get the $2.9bn figure.

But the contract was reviewed annually, meaning renewing it until 2028 was not guaranteed.

A source familiar with this contract – who spoke on condition of anonymity – told BBC Verify that Doge’s figure is “based on speculative, never-used figures” and that the actual spending depended on how many children were placed at the facility and the services they required.

“In truth, the government never incurred those costs and could never reach that ceiling amount. The real, documentable savings from early termination were approximately $153 million”, they estimated.

They say this figure comes from tallying up the $18m per month fixed running costs (for things like staffing and security at the facility) from February – when Doge announced the cut – to November – when the contract was subject to annual review.

They also told us that the site – which closed on the same day as the Doge announcement – never reached its maximum capacity of 3,000 children, and about 2,000 stayed at the Texas facility at its peak, before numbers fell significantly as border crossings decreased.

We contacted the Administration for Children and Families and the Department for Health and Human Services which awarded the contract but are yet to hear back.

The second largest saving listed by Doge comes from cancelling a contract between the Internal Revenue Service (IRS) and an IT company called Centennial Technologies which it claims was worth $1.9bn.

The document which Doge links to has a total contract value of $1.9bn and all of the other cost fields, including the amount already spent, are for $0.

However, Mr Drabkin told us this does not necessarily mean that nothing had been spent on the contract.

He said several government departments have poor recording keeping, meaning the amount spent during some contracts might not always be updated in a timely fashion.

The contract start date is listed as August 2024 and was estimated to run until 2031.

However, Centennial Technologies’ CEO told the New York Times that the agreement had actually been cancelled last autumn during the Biden administration.

The company did not respond to our requests for further comment.

Another IT contract, this time with the Department of Defense, is the third largest claimed saving.

Doge says $1.76bn was saved by cancelling a contract with an IT services company called A1FEDIMPACT.

On the contract document, the total value is listed as $2.4bn. An online database of government contracts called Higher Gov says this amount was the ceiling value.

Again, there is $0 recorded for the amount that had been spent at the time the contract was terminated.

It is unclear where Doge’s figure of $1.76bn comes from – we have asked the Pentagon and the supplier about it.

The fourth largest claimed saving of $1.75bn comes from cancelling a USAID grant to Gavi, a global health organisation, which campaigns to improve access to vaccines.

Doge links to a page on USASpending.gov. It shows a grant was paid to Gavi in three instalments, during the Biden administration, totalling $880m.

Gavi confirmed that $880m had been paid out by USAID but said it had not been told the grant had been terminated.

“Gavi has not received a termination notice related to this grant,” a spokesperson told us.

We have not found any evidence for the $1.75bn saving claimed by Doge, and a source familiar with the contract said it was unclear where it comes from.

We asked the USAID Office of Inspector General about the grant but it did not respond to us.

While Doge may have cut a significant amount of government spending, the lack of evidence provided for its biggest claimed savings makes it impossible to independently confirm exactly how much.

Doge does not have a press office but BBC Verify has contacted the White House to ask for more evidence of these claimed savings.

Additional reporting by Ned Davies and Alison Benjamin.