Buchanan was previously product development manager at Just Retirement and product manager, lifetime mortgages, at Prudential.
Legal & General launched its own brand of lifetime mortgage products in July.
Steve Ellis, director, lifetime lending, Legal & General Home Finance, said: “Chris is an experienced senior hire who knows the retirement lending sector inside out and will give us a real strength and depth when it comes to product development and innovative solutions to meet the needs of customers.
“Chris's appointment signifies our intent to build a market-defining retirement lending proposition to complement our existing individual retirement solutions.”
Buchanan added: “In recent times, and especially since the Mortgage Market Review, the industry has recognised a significant customer need for retirement lending products, not only for customers’ currently in retirement, but also for customers of working age requiring mortgage terms that extend well into their retirement years.
“At Legal & General Home Finance we’re working on a number of innovative retirement lending products and I’m really excited about the opportunity of working with such a great team to deliver something new to this sector.”