Can I deduct monthly federal tax payments as part of a payment plan for a previous tax year? If so where would I enter that?

No, Federal income tax is never deductible.

However, some states allow you to deduct it (but not any interest or penalties) on your State return.

There are six states that allow you to enter the federal tax you paid on your state return--Alabama, Iowa. Louisiana, Missouri, Montana, and Oregon.  If you are filing in one of these states watch for the deduction when you prepare your state return.