Just one-in-four of the current Cabinet are members of KiwiSaver, with the majority enrolled in other superannuation schemes.
The Budget on Thursday will include a reduction to the KiwiSaver tax credit, with contributions from workers and employers set to rise after the election on 26 November.
The latest MPs' Register of Pecuniary Interest shows just five out of 20 Cabinet ministers contribute to the voluntary workplace savings scheme.
Neither Prime Minister John Key nor Finance Minister Bill English are listed as KiwiSaver members.
The register lists the financial interests of all MPs, although the widespread use of trusts means the exact nature of those interests is not always clear.
Independent MP Chris Carter and Maori Party MP Rahui Katene did not file their returns on time.
Carpet, pictures, Grand Prix tickets and a decorated ostrich egg are among the gifts received by Mr Key over the past year.
The gifts are revealed in the Register of Pecuniary Interest, which requires MPs to list gifts worth more than $500.
Mr Key received a red and cream carpet from the President of Afghanistan, Formula 1 tickets from the Singapore government and a samurai "art" sword from a Japanese school.
The Prime Minister was also given a range of pictures, other sports tickets, signed sports uniforms and an annual subscription to the Remuera Golf Club.
The ostrich egg was jointly given to Mr Key by the Korean Society of New Zealand Rugby Union and the Egg Art Foundation of New Zealand.