How to calculate the different portions of deductions by state?

[al-kofahi1986]

I worked in 3 different States in 2019, and when filing my state tax, I am being asked to "Enter the non-State (in this case Massachusetts) portion of the amount you paid during 2019 to social security (FICA), railroad, medicare, US or Massachusetts retirement"? How would I know how much is for each State portion?

[AmyC]

Take each state and divide by the total. Take the MA income and divide it by your total income. Multiply that percentage times  the total of each category.

For example:

• You earned $10,000 in MA and $40,000 total on all W2s.
• ($40,000 total - $10,000 MA = $30,000 non-MA income - see more below)
• $10,000  MA divided by $40,000 total  equals  25%.
• Add up all the Medicare on all W2 forms.
• Multiple the total  Medicare by 25%,
• Add up all the Social Security on all W2 forms
• Multiply Social Security by 25% and so on.
• Keep adding and multiplying as needed

If you need it the other way around, you can do the non-MA

• $30,000 non MA divided by $40,000 total  equals  75%.
• Add up all the Medicare on all W2 forms.
• Multiple the total  Medicare by 75%,
• Add up all the Social Security on all W2 forms
• Multiply Social Security by 75% and so on.
• Keep adding and multiplying

If all income on the W2 was MA, no math required. Just look at the form.