Extra withholding

[SPR48]

I claim zero and pay every year. Is it worth it to add extra withholding or put this extra money in TSP account. 

[kcumberland]

The Thrift Savings Plan (TSP) is a great way to save for your retirement while reducing your Federal Taxable income.  Your contributions are pre-taxed, which means the more money you put into the savings, the more you can reduce the income that is taxable. 

However, you should also review your W4 to ensure that you are withholding the correct amount, as your withholding will change, also. The W4 Calculator is a great way to determine if your current W4 is correct. Then look at your TSP to determine how contributing will change your taxable income.

https://turbotax.intuit.com/tax-tools/calculators/w4/