Ok, I thought this was a replacement plan, not a delay plan. Remember that the 401k contribution limit is $18K. There are other tax deferred investment plans that don't require employer participation. I really doubt it will change much to have one more way to make tax deferred savings plan contributions. Plus, your way has the added cost of delaying SS payouts! Also, I'd point out that SS payouts can start well before retirement age, as there are features such as support for disability, for education of minor dependents, etc. And, the SS payout start date isn't just one date - it's a range of dates from which the principle may choose - each with different payout amounts.