According to Sunday Mirror, the singer's management decided to take out a policy to protect his vocal chords last week.
A source told the paper: "Insurance for stars is a big deal in the US and Adam's voice is his bacon. He had it insured last week."
Lambert joins a host of other stars who are rumoured to have insured their body parts. Mariah Carey is said to have taken out a $1bn (£622m) policy to cover her legs, while Dolly Parton has allegedly insured her famous 40DD chest for $600,000 (£373,000).
Over the summer, Lambert collaborated with Queen and played a series of dates at the HMV Hammersmith Apollo. He also took to Twitter to reassure fans that he will be touring in support of his latest LP Trespassing "when the time is right".
It was recently revealed that the 30-year-old - who finished as runner-up in the eighth season of American Idol - will make a guest appearance in hit US show Pretty Little Liars next month.
Watch the video for Adam Lambert's 'Never Close Our Eyes' below: