If I make payments every month on a medical bill can my wages still be garnished or my credit be affected and is there a minimum payment amount to show good faith in Colorado?

I am not an atty in CO nor an atty at all but good ole common sense seems to tell me that if you are making payments as agreed and the creditor has agreed to such, then how could the lender explain to a court the reason for the need to garnish you paychecks. I suppose they could legally and the court would probably grant them such authority?

To garnish your wages tey have to obtain a judgement against you. This means a court hearing. You don't say whether what you are paying is as per an agreement with the creditor. If its not, they still might deicde to sue and report it to credit bureaus.

If the bill is late and due and you can not pay in full, yes they can make note of it being late on your credit report.

If you have a written agreement to pay this, then you are OK, But if there is not a written agreement, they can demand full payment if they want to