A Social Security change that goes into affect at the end of April could cost some couples $100,000 or more in lost benefits, according to financial advisors.

Advisors say they have been contacting their clients since the change was announced in December to determine what the clients want to do.

“There could be a $100,000 differential for some clients between using the strategy that is being eliminated and not using it,” says Peter Doyle, senior advisor with Huber Financial Advisors in Lincolnshire, Ill.

David Leland, managing director, wealth management, for Merrill Lynch in Boston, agrees.  “The change is not going to affect a lot of people, but it could impact some a lot.”

The Social Security Administration announced in December that a strategy known as file and suspend would no longer be available after April 30. The claiming strategy is used mostly by couples and divorcees.

Under this strategy, the higher earner files for Social Security benefits when he or she reaches full retirement age but then suspends the claim. The spouse can then claim benefits on the other person’s record. The higher earner lets his or her benefits continue to grow until age 70, and in some cases, the spouse is also able to let his or her own benefits grow as well until age 70.

Anyone wanting to use this strategy to maximize benefits has until the end of April to apply. Couples already using this claiming option will not be affected.

Amanda Lott, partner and wealth advisor for RegentAtlantic, a registered investment advisor in Morristown, N.J., says people of retirement age should contact their advisors to see if this strategy is advantageous. In addition, advisors should be contacting their retirement-age clients to inform them of the change. Lott wrote an article for Financial Advisor magazine about the strategy.

“This only affects a subset of our clients,” says Doyle, “but we do not want to see someone who was planning to use this strategy in order to increase their benefits get shut out.” One member of a couple has to file for benefits in order for the other to claim spousal benefits.

Doyle talked to one couple who are clients in early March who were thinking of using the file-and-suspend claiming option at some point. They accelerated their plans in order to meet the deadline, he says.