The Treasury has confirmed new European rules outlawing the use of gender in underwriting will not affect policies taken out before 21 December 2012.
The European Court of Justice made a ruling on the matter earlier this year, saying it constituted a form of discrimination.
In a written ministerial statement today, financial secretary Mark Hoban said: "The Government's view is that the judgment only applies to new contracts for insurance and related financial services entered into on or after 21 December 2012.
"In such contracts, the use of gender as a risk factor should not result in individual differences in premiums and benefits for men and women.
"However, any contracts with gender-sensitive pricing of premiums or benefits concluded ahead of 21 December 2012 can continue unchanged after that date."
Otto Thoresen, director general of the Association of British Insurers, said the clarification was "good news" for pensioners who would have been affected retrospectively.
He added: "The decision by the European Court to ban gender in the use of insurance pricing was disappointing as it could have an impact on our customers.
"Insurers are working hard to mitigate any effects and today's confirmation that the new rules will only apply to policies taken out from 21 December 2012 will certainly help."