Excess contribution to 401k

[satya1224]

Hi,

I have contributed $9500 excess (employer part) to solo 401k account. I have filed extension for my returns but I have already filed my return few days ago. My CPA said, taxes are paid on $9500. Can I let the amount remain in 401k account and consider that toward next year contribution? or What corrective action can I take?

Thank you in advance.