# Johnny.Decimal filing

> **Give every kind of document in your practice a short number,** like `21.01 Bank statements`, and use that same number everywhere: your file folders, your email labels, and your notes.

Johnny.Decimal is a free, well-documented filing system created by Johnny Noble. This page covers how it works and how I lay it out for my solo practice. The full method is at the source:

- **[johnnydecimal.com](https://johnnydecimal.com)**: start with the **[Introduction](https://johnnydecimal.com/documentation/introduction)**, then **[Areas and categories](https://johnnydecimal.com/documentation/areas-and-categories)**, **[IDs](https://johnnydecimal.com/documentation/ids)**, **[The JDex](https://johnnydecimal.com/documentation/the-jdex)**, and **[Saving files](https://johnnydecimal.com/documentation/saving-files)**
- **[Forum](https://forum.johnnydecimal.com/)**, where people share their systems
- **[Products](https://johnnydecimal.com/products)**, paid ready-made systems (including one for small-business admin) and courses; the free documentation is enough to build your own

---

## How it works

Three levels, never more than ten choices at any of them.

| Level | Looks like | What it is |
|---|---|---|
| **Area** | `20–29 Finances` | A broad part of your life or business. At most ten, numbered in tens. |
| **Category** | `21 Banking & bookkeeping` | A drawer inside an area. At most ten per area (21 through 29). |
| **ID** | `21.01 Bank statements` | A folder that holds files: the category number, a decimal point, then 01, 02, 03… |

**The rules:**

- **Nothing goes deeper than an ID.** No subfolders; a crowded ID is usually two IDs.
- **No more than ten** at any level, so you can find anything in three steps.
- **Numbers don't move.** Numbered folders sort the same everywhere, and "it's in 21.01" is quicker than a path.
- **Same number everywhere:** the folder on your drive, the label in your email, and the heading in your notes.

## The JDex: your index

The **JDex** is a list of every ID, usually in a notes app: one entry per ID with its number, name, and where its stuff lives (folder, email label, app). In the creator's words, *"The index is your Johnny.Decimal system."* It's where you decide where something goes before you file it, and what stops you creating `21.07 Bank stuff` next to `21.01 Bank statements`.

---

## A sample layout for a solo practice

An illustration only; build yours from the documents you actually have.

```
10–19  Practice administration
       11  Licenses & credentials
           11.01  State license ([State])
           11.02  NPI, CAQH & registrations
           11.03  Malpractice insurance
           11.04  CE certificates
       12  HIPAA & compliance
           12.01  Policies & procedures
           12.02  Security risk analysis
           12.03  Vendor BAAs
           12.04  HIPAA process log
       13  Software & vendors
           13.01  EHR account & settings
           13.02  Email & cloud (Workspace / Microsoft 365)

20–29  Finances
       21  Banking & bookkeeping
           21.01  Bank statements
           21.02  Monthly close
           21.03  Card processor reports
       22  Taxes
           22.01  Quarterly estimates
           22.02  Annual return & CPA correspondence
       23  Expenses & receipts
           23.01  Receipts
           23.02  Mileage log

30–39  Marketing & referrals
       31  Directories
           31.01  Psychology Today
           31.02  [Second directory]
       32  Referral partners
           32.01  Referral tracker
           32.02  Letters & one-pagers
       33  Website
           33.01  Site copy & images
           33.02  Domain & DNS records
```

**Client records aren't here.** They live in your electronic health record (EHR) system, covered by a business associate agreement (BAA). Keeping this tree to the business side is also what makes it safe to use with a general-purpose AI assistant.

**Personal admin can share the tree,** as an area like `40–49 Home`.

---

## Why it pairs well with AI

A numbered tree is easy for an assistant to work with (see [using AI to run the practice](https://toolkit.marcusberley.com/using-ai/)):

- **"File this in 23.01"** can't be misread the way "put it with the other receipts" can.
- **The JDex is its map,** including when to ask you instead of guessing.
- **Scans come out clean:** it reads each one, names it `2026-03-14 [Vendor] - [What it is].pdf`, and proposes an ID for you to approve.
- **Routines point to fixed places:** "the monthly close reads exports from 21.01 and writes its summary to 21.02."

---

## Getting started

1. **Read the [Introduction](https://johnnydecimal.com/documentation/introduction).** It takes 10 minutes.
2. **List the *kinds* of things you keep,** from your downloads folder, desktop, and email. Don't sort yet.
3. **Group them into areas and categories on paper,** three to five areas to start.
4. **Start the JDex**, one note per ID, before you create any folders.
5. **Make the folders and move things in one category at a time,** starting with what you hunt for most (usually finances).
6. **Match your email labels** to the same numbers as you go.
7. **Expect to adjust for a month.** After that, a new document takes seconds to place.