403(b) question - contribute post tax year

[slara22]

Hello -

Can I make a larger contribution to my 403(b) in  2025, and make it retroactive to tax year 2024? With contributions to IRA's one can contribute in the current year (2025) and have them count as prior year contributions (2024 tax year). Wondering if the same applies to 403(b)'s.

The context: I was unemployed until September 2024. My elected 403(b) contributions September to December 2024 were about $6000. I am allowed much more (plus I am over 50) and can afford to contribute more.  I would also like to lower my tax bill. 

Is this possible just like it is with traditional IRA's? Thank you!

[DianeW777]

It depends. Check your employer's plan year and inquire with the plan administrator as to when the last day would be for additional contributions for 2024.

• The deadline for employer contributions to a 403(b) plan for the 2024 calendar year depends on the employer's fiscal year and the plan's type. 
• For a 403(b) plan that is a money-purchase plan (a relatively rare occurrence), there is a minimum funding deadline of 8.5 months following the close of the plan year (September 15 for calendar year plans). After 8.5 months, the contribution can still be made, but it is subject to a 10% excise tax.