I’m a trustee in Idaho. All assets are in stocks. Two beneficiaries live in CA. Must I do CA State K-1s, or can they file Fed K-1’s with their CA returns?

The trust would need to file a CA Form 541 if:

 

• The trustee or beneficiary (non-contingent) is a California resident
• The trust has income from a California source
• Income is distributed to a California resident beneficiary

And the trust has:

• Gross income is over $10,000
• Net income is over $100

 

See https://www.ftb.ca.gov/file/personal/filing-situations/estates-and-trusts/index.html