4137x -

: It determines the employee's share of FICA (Social Security and Medicare) taxes on tips that weren't taxed during the year .

: The form applies a 6.2% Social Security tax (up to a wage limit, such as $176,100 for 2025) and a 1.45% Medicare tax on every dollar of unreported tips . : It determines the employee's share of FICA

IRS is the tax document used to calculate and report the Social Security and Medicare taxes owed on unreported tip income . This includes cash tips, noncash tips, and "allocated tips" shown in Box 8 of your Form W-2 that were not previously reported to your employer . Core Purpose of Form 4137 This includes cash tips, noncash tips, and "allocated

: Failure to report required tips to your employer can lead to a penalty equal to 50% of the Social Security and Medicare taxes due on those tips . This includes cash tips

: Unreported income is not credited to your Social Security history, potentially lowering your future monthly benefit payments .