Assuming that you are a US citizen/ resident and because your husband was admitted into the country under a visa ( K-1), he would be treated as a non-resident alien till the issuance of the green card ( chnage of status). But being a non-resident alien does not take away the requirement to have health insurance under the ACA. I am assuming that he was working in the USA while awaiting the green card-- did his employer not provide health insurance or was he self-employed ?
Since he had no income and absent any other restrictions, you could file Married Filing Sep ---- thus he would have income only for part of the year and be covered by the employer and you file similarly but with your whole year health insurance. This may or may not help -- cannot say without knowing your exact facts and circumstances