Yes, TurboTax will accept blanks for January and February. Don't enter $0's.
Be sure you indicated at the beginning of the Health Insurance section that 'I'll choose who had it and for which months' so that you could not check the boxes for January and February on the following screen (screenshot).
Here's more info:
https://ttlc.intuit.com/replies/6613869
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"