Every January, someone tells you what you should have done in December. This is the article that gets there first. If you are over fifty and behind on retirement savings — which, for the record, is most people — the last months of the year are when a handful of deadlines quietly matter. None of them require heroics. A couple of them are worth real money.
The December 31 deadlines
Workplace plan contributions. Money going into a 401(k) or 403(b) has to be in by December 31 to count for this year. For 2026 the employee limit is $24,500, and if you are fifty or older you can add a catch-up contribution of $8,000 on top. Between sixty and sixty-three there is an even larger catch-up available — $11,250 instead — a recent rule most eligible people still have not heard of. You do not need to hit the maximums for this to matter. If there is slack in your budget as the year ends, raising your contribution percentage for the final pay periods is the single most direct move available.
Required minimum distributions. If you are seventy-three or older, your RMD generally must come out by December 31, and the penalty for missing it is genuinely painful. If a parent in their eighties leans on you for paperwork help, this is the one to check for them too.
The deadline that is later than you think
IRA contributions are the merciful exception: you have until tax filing day next April to make a contribution that counts for 2026. The limit this year is $7,500, plus a $1,100 catch-up if you are fifty or older. So if December is tight — and December is always tight — the IRA is the one you can defer to a calmer month without losing the year.
One rule change worth knowing about
If you earned more than $150,000 in wages last year, your 401(k) catch-up contributions now have to go in as Roth — after-tax — rather than traditional. It is not a bad thing, but it can surprise people at tax time. Your plan administrator handles the mechanics; you just want to know which bucket your money is landing in.
What this is really about
None of these moves will transform a retirement on their own. What they do is compound. The final ten or fifteen working years are, for most late starters, the most powerful saving years of their lives — higher income, lower expenses, bigger limits. December is simply when the door closes on this year’s slice of that. Close it with something inside.