Key Takeaways Older workers were the most likely to max out their 401(k)s, according to a recent report. Those who feel behind on saving can improve their outlook by increasing contributions, delaying Social Security, or working longer. The group least likely to max out their 401(k) plan was workers younger than 25, with only 3% of this cohort contributing up to the limit. Older workers, in particular, are vulnerable to having inadequate savings for retirement. However, not all hope is lost for older workers.