For what it's worth, here's how we file. Each provider has three files.
File folder 1: Provider information, W-9, licenses and certifications, contract information, communications worth saving, etc.
File folder 2: Patient registration forms and superbills. These are filed alphabetically. For our smaller practices, it's just one folder. For larger practices, it's multiple folders, A-G, H-M, etc. For large practices, it's one folder per letter. I only file by the first letter of their last name, not any further. For example, all the Millers, McNarys and Matsumotos are in the M folder. I do not take the time to make sure it's Matsumoto, then McNary and finally Miller (I'd be filing all day!)
File folder 3: EOBs. These are filed chronologically by the date on the EOB. Again, for our small practices, it's just one folder and we file each EOB behind the rest. For larger practices, we have 12 folders, one for each month of the year. Any problem insurance companies get their own folder.
We frequently have to go back and look at the original document, and this system has served me well for many years. I am now using a web-based billing program that has online document storage. This has been a great time saver--the documents are just a click away instead of having to search in a file folder. I have looked into electronic file storage, but it was too expensive. And with the document storage right on the billing program, it became a moot point.
I keep two years worth of files in the filing cabinet. Every January I pull older superbills and EOBs out, put them in a box, label it and put it in the crawl space under the house. It really doesn't take that long and it feels so good to get rid of those old papers! (I have also hired teenagers to do this for me when I am too busy.) I have also hired a professional shredding company to come and take the 7+ year old boxes off my hands.
Hope this helps!
~Kelli