Information published by the Independent Parliamentary Standards Authority (IPSA) shows that £170,576.24 was spent on security assistance in 2015/16.
This sum increased 15-fold to £2,550,954.22 in 2016/17, IPSA said.
Ruth Evans, chair of the authority, said: "Following the tragic events of June 2016, there was a big increase in the total expenditure on security, rising to £2.5 million during this year.
"It is important that we take the security of MPs, and that of their families and their staff, very seriously."
IPSA said a standard package of security measures is available to all MPs that has been recommended by security advisers and the police.
Enhanced measures can be offered to MPs upon recommendation by the police, the authority added.
Ms Cox was murdered by right-wing extremist Thomas Mair as she arrived to host a surgery in her Batley and Spen constituency last June.
Earlier this year, a coat of arms was unveiled in Parliament to honour the Labour MP.
Inspired by her maiden speech, the plaque bears the motto "More in Common", with elements to show off her love of rivers and mountains and her support for women, as well as four red roses to represent each of her family members, two red for Labour and two white for Yorkshire.