Any rules for how long a creditor can wait to report a delinquincy?

[Sooqs]

I have been working very hard for years to rebuild my credit. I was getting close to the  700 mark, as my mess ups as a teenager rolled off. Then, two weeks ago, a medical debt popped up from 2012. Now, in 2012 I had already started trying to repair my credit, so I am actually fairly sure I paid the bill. I just have no clue how to prove that three years later.

Are there any rules that dictate the time they have to report this?

How do I know it is worth disputing?

[RobertEG]

No.

The FCRA only requires that information reported must not knowingly be inaccurate.

There are no requirements that they must report, or how long after the fact they must report.

What they must report is the month and year that the delinquency occured, as the CRA needs that date to assess when they must exclude the delinquency from credit reports they issue.