The lender said it is still working out when it will launch offers under the scheme and the specifics of the products it will offer.
A Barclays spokesman said: "We are pleased to confirm that Barclays will participate in the Help to Buy mortgage guarantee scheme."
Barclays joins other major UK lenders RBS, Lloyds, HSBC and Santander UK in signing up for the scheme.
Customer owned Nationwide is the only big lender to not commit to the scheme but has said it is considering the plan.
