One challenge a young adult may face in her first year of independent tax filing is verifying income, since one of the prime sources of income data is a prior year tax return. However, other methods of verification are available; for instance, the Marketplace will have access to monthly wage data that can verify current income. In the case of someone who is self-employed or who has fluctuating income, additional documentation of income may be accepted.
The fact that a young adult has not filed in the past will not prevent her from receiving premium tax credits. When she applies, if the Marketplace cannot verify her income right away, she will receive a provisional (temporary) eligibility determination based on the income information she puts in her application. The Marketplace will then give her a period of time (usually 90 days) to provide additional documentation of income. Current pay stubs, bank deposit records, or other documentation may be appropriate, depending on her situation.