If you were offered health insurance through a job, and the lowest-priced coverage available to you for just your own coverage would have cost you more than 8% of your household income, then it was unaffordable.
If you or your spouse were offered health insurance through a job and covering your whole family would cost more than 8% of your household income, it's considered unaffordable. But if the coverage for you or your spouse individually did not cost more than 8% of your income, then insurance was only unaffordable for the rest of the family.
Example: Cecilia and Pat are married with two children, Alberto and Alicia. Pat's job offered her health insurance, but it would have cost a total of $20,000 to insure the whole family for 2018. To insure Pat alone, it would have cost $5,000 for the year. The family's household income is $90,000. Since $5,000 is not more than 8% of $90,000, Pat is not eligible to get the penalty for not having health insurance waived. However, since $20,000 is more than 8% of their $90,000 household income, Cecilia, Alberto and Alicia are all eligible to get the penalty waived.
If you're married without children and both you and your spouse were offered health insurance through a job, it's unaffordable if the combined cost of coverage for both of you was more than 8% of your household income. But if either of you were offered a family plan that cost less than 8% of your household income, coverage was affordable.
Example: Joanna and Dan are married without children and both of them have jobs. Joanna was offered health insurance through her job that would have cost 5% of her and Dan's household income. Dan's lowest-priced health insurance option through his job also cost 5% of his and Joanna's household income. Joanna and Dan are both eligible to get the penalty for not having health insurance waived because together, their insurance was unaffordable.
If you were only offered coverage for part of the year, it's OK. You can calculate whether it was affordable by multiplying the monthly premium by the 12 months of the year. If that number is more than 8% of your annual household income, health insurance was unaffordable.
The health insurance marketplace will follow up to confirm the details of the health insurance plan you or your spouse were offered through your job.