Here’s a clear, factual write-up: What is “Form 64”? There is no standalone IRS or federal “Form 64” for the Advance Premium Tax Credit (APTC). The correct form for reconciling APTC on a federal tax return is Form 8962 (Premium Tax Credit).
It seems you’re looking for a (explanation or summary) about “Form 64” related to APTC (Advance Premium Tax Credit) in a PDF context. aptc form 64 pdf