This article uses a microsimulation model to estimate how freezing all remaining private-sector and one-third of all public-sector defined benefit (DB) pension plans over the next 5 years would affect retirement incomes of baby boomers. If frozen plans were supplemented with new or enhanced defined contribution (DC) retirement plans, there would be more losers than winners, and average family incomes would decline. The decline in family income would be much larger for last-wave boomers born from 1961 through 1965 than for those born from 1946 through 1950, because younger boomers are more likely to have their DB pensions frozen with relatively little job tenure. Higher DC accruals would raise retirement incomes for some families by more than their lost DB benefits. But about 26 percent of last-wave boomers would have lower family incomes at age 67, and only 11 percent would see their income increase.