The Treasury select committee has called the FCA and Apfa to give evidence on last week’s Budget.
MPs will quiz FCA director of long-term savings and pensions Nick Poyntz-Wright on last week’s shake-up of retirement income.
Poyntz-Wright will appear alongside FCA head of savings, investments and distribution David Geale.
Apfa director-general Chris Hannant will also field questions alongside NAPF chief executive Joanne Segars and Building Societies Association chief executive Robin Fieth.
Last week, the Chancellor said savers aged 55 and over would be able to take their pension pot in cash from next April.
The Treasury also pledged guaranteed at-retirement guidance for everyone.
The FCA is responsible for designing the guidance regime and will face questions over its plans.
The regulator has also just completed a review of the annuities market and will start a market study due to complete next year.
The Association of British Insurers has called for an FCA rethink in light of major market changes.
Pensions consultant Ros Altmann and Age UK head of public policy Jane Vass will also give evidence to MPs
On Thursday Chancellor George Osborne will answer questions to complete MPs’ investigations on the Budget.