The pay packet consists of €370,136 in a basic salary, and a further €49,966 allotted for allowances.
The latter figure of almost €50,000 is “a payment in lieu of pension contribution” according to the HSE.
A HSE spokeswoman told Mr Deegan that Reid “is not a member of the HSE pension scheme and €49,966 is a payment in lieu of pension contribution”.
“The rates of pay, allowances and other pay-related conditions for HSE employees are approved by the Department of Health,” she said.
Reid began his post in May 2019 on a salary of €229,194 per annum and is now in the second year of a five year contract.
The largest employer in the state, last year saw the number of HSE workers receiving over €100,000 salaries increase from 534 in 2019 to 678 in 2020.
Reid was the only non-medical staffer to receive more than €200,000 in 2020, whilst 36 managerial staff received salaries between €150,000 and €200,000.
“In 2020, there was a restoration of periodic allowances culminating in an increase of 5pc for those earning less than €125,000 and 8pc for those earning more than €125,000,” the HSE FOI unit told Mr. Deegan.