@jimtony for your ref. below are links to (a) the totalization agreement between US-SSA and Norway- National Insurance -->
https://www.ssa.gov/international/Agreement_Texts/norway.html#agreement
and (b) Tax Treaty between US and Kingdom of Norway --> https://www.irs.gov/pub/irs-trty/norway.pdf
Assuming that your employer in Norway did NOT send /re-assign you to the USA, you being a Green Card ( Immigrant ) in the USA, you come under the tax and Social Security laws of the USA.
Generally US considers earnings to be sourced where the work is performed and so does Norway for most part ( there are carve outs).
1. Thus based on the fact that you are working remotely for an entity in Norway ( even if they consider you an employee-- which would be wrong under the treaty ), you would be considered a self-employed / contractor performing tasks for a foreign entity.
2. This would also mean that your home state ( where you are domiciled, driver's license etc. ), would consider your income as in-state sourced . Most states tax you on your world income and give credits for taxes paid to other states ( US) for any out-of state sourced income
3. Yes , you will have to file form 8802 to request a certificate of residency ( 6601) for treaty condition assertions, that will allow you to stop paying taxes and social security to Norway.
4. Prior to your moving to USA, any income for the year 2022 earned in Norway would be taxed by Norway. However, from the day you entered USA with your Green Card, you are resident of USA and taxed on your world income by the USA. Since your earnings in the USA ( as a self-employed) has not been withheld -- you need to make estimated payments for federal and State taxes quarterly -- i.e. you must meet your obligations quarterly or be subject to interest and penalties. There are ways around this, though.
5. Can TurboTax do all this for you ? YES.
6. Without more information ( when did you enter the country, did you come in with green card or with a K-Visa and if so when , approximate first date of earnings in the USA, rough quarterly income, are you the sole earner or your spouse works , if working does he/she uses a zero deduction on W-4 etc. etc. ) we cannot really guide you as to how much your quarterly estimated payments should be . Or you can use current version of TurboTax ( 2021 ) to compute a dummy return ( Joint) using 2021 brackets but 2022 estimated incomes and use that for estimated payments . Or you can seek a tax professional familiar with international situations.
Does this help? Is there more I can do for you?
pk
