If you are allocating percentages for a 1095-A, you should be able to look at a copy of his Form 8962 Part IV and find the allocation percentage assigned to you. If it is empty, you can assume he used 100% and your percentage is zero. You can also ask his preparer what percentage the preparer used. Failing an answer from either location, you can file a Request for Copy of Tax Return with the IRS, but this will take some time.
Please see this TurboTax FAQ for instructions on entering a Form 1095-A and generating the Form 8962 requested by the IRS:
https://ttlc.intuit.com/replies/6765257
