> ## Documentation Index
> Fetch the complete documentation index at: https://docs.terrapinfinance.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Use of Funds Taxonomy

> Classification system for US municipal bond proceeds

The Use of Funds Taxonomy provides a standardized, hierarchical classification system for categorizing how **US municipal bond** proceeds are used. This three-level hierarchy helps investors understand and analyze US municipal bonds based on their intended purpose.

## Taxonomy Structure

The taxonomy consists of three levels, from broadest to most specific:

1. **Use Sector** (Top Level) - 10 broad sectors representing major areas of public infrastructure and services
2. **Use Category** (Middle Level) - 31 categories providing more specific functional classifications
3. **Uses of Proceeds** (Bottom Level) - 73 specific uses describing the precise purpose of bond proceeds

### How the Hierarchy Works

Each bond's use of proceeds maps to exactly one category, and each category belongs to exactly one sector. This creates a clear hierarchical relationship:

**Use Sector → Use Category → Uses of Proceeds**

For example:

* **Sector**: transportation
* **Category**: airport
* **Proceeds**: airport

Or a more complex example:

* **Sector**: education
* **Category**: higher education
* **Proceeds**: public college, private college, community college, or student housing

### Important Note

A single bond may have multiple sectors or categories if the uses of proceeds are diverse enough. For example, a bond that funds both a hospital and a school would be classified under both the healthcare and education sectors.

## Complete Taxonomy Reference

The table below shows all possible values across the three-level hierarchy. The sector is shown only on the first row of each sector group for readability.

| Use Sector         | Use Category                        | Uses of Proceeds                                                                                                     |
| ------------------ | ----------------------------------- | -------------------------------------------------------------------------------------------------------------------- |
| **development**    | **economic development**            | **development district**, **hospitality**, **office buildings**, **public buildings**, **shopping centres**          |
|                    | **industrial development**          | **industrial development**, **pollution control**                                                                    |
| **education**      | **higher education**                | **community college**, **private college**, **public college**, **student housing**                                  |
|                    | **pre-school**                      | **pre-school and daycare**                                                                                           |
|                    | **primary and secondary education** | **charter school**, **public school district**, **standalone public school**                                         |
| **government**     | **essential services**              | **correctional facilities**, **courts**, **fire**, **police**                                                        |
|                    | **general purpose**                 | **tribal**                                                                                                           |
| **healthcare**     | **health system**                   | **health system**                                                                                                    |
|                    | **hospitals**                       | **critical access hospital**, **specialty hospital**, **standalone hospital**                                        |
|                    | **senior living**                   | **assisted living**, **continuing care retirement community**, **independent living**, **nursing home**              |
| **housing**        | **military housing**                | **military housing**                                                                                                 |
|                    | **multi-family housing**            | **local hfa multi-family housing**, **local standalone multi-family housing**, **state hfa multi-family housing**    |
|                    | **public housing**                  | **public housing**                                                                                                   |
|                    | **single family housing**           | **local hfa single family housing**, **local standalone single family housing**, **state hfa single family housing** |
| **miscellaneous**  | **miscellaneous**                   | **miscellaneous**                                                                                                    |
| **recreation**     | **culture**                         | **community centre**, **library**, **museum**                                                                        |
|                    | **recreational**                    | **parks**, **stadium**                                                                                               |
| **securitized**    | **gas prepay**                      | **gas prepay**                                                                                                       |
|                    | **student loan**                    | **student loan**                                                                                                     |
| **transportation** | **airport**                         | **airport**                                                                                                          |
|                    | **bridges**                         | **non-toll bridges**, **regional toll bridges**, **state toll bridges**                                              |
|                    | **parking**                         | **parking facilities**                                                                                               |
|                    | **port**                            | **combined port authority**, **standalone port**                                                                     |
|                    | **public transit**                  | **buses**, **ferries**, **trains**                                                                                   |
|                    | **roads**                           | **non-toll roads**, **regional toll roads**, **state toll roads**                                                    |
| **utility**        | **communication**                   | **broadband**, **telephone**                                                                                         |
|                    | **electrical**                      | **electrical infrastructure**                                                                                        |
|                    | **gas**                             | **gas infrastructure**                                                                                               |
|                    | **power**                           | **alternative source power**, **coal power**, **gas power**, **nuclear power**, **solar power**, **wind power**      |
|                    | **waste removal**                   | **waste removal**                                                                                                    |
|                    | **water and sewer**                 | **flood control**, **irrigation**, **sewer**, **storm water**, **water**                                             |

## API Fields

The taxonomy is available through three fields in our US municipal bonds API:

### use\_sectors

Array of sectors (top level). Returns the broadest classification for a bond's use of funds.

**Example values**: `["education"]`, `["transportation"]`, `["utility"]`

**Available sectors (10 total)**:

* `development`
* `education`
* `government`
* `healthcare`
* `housing`
* `miscellaneous`
* `recreation`
* `securitized`
* `transportation`
* `utility`

### use\_categories

Array of categories (middle level). Returns more specific functional classifications.

**Example values**: `["higher education"]`, `["airport"]`, `["power"]`

**Available categories (31 total)**:

* `airport`
* `bridges`
* `communication`
* `culture`
* `economic development`
* `electrical`
* `essential services`
* `gas`
* `gas prepay`
* `general purpose`
* `health system`
* `higher education`
* `hospitals`
* `industrial development`
* `military housing`
* `miscellaneous`
* `multi-family housing`
* `parking`
* `port`
* `power`
* `pre-school`
* `primary and secondary education`
* `public housing`
* `public transit`
* `recreational`
* `roads`
* `senior living`
* `single family housing`
* `student loan`
* `waste removal`
* `water and sewer`

### uses\_of\_proceeds

Array of specific uses (bottom level). Returns the most detailed classification of how bond proceeds are used.

**Example values**: `["public college"]`, `["airport"]`, `["solar power"]`

**Available uses (73 total)**:

* `airport`
* `alternative source power`
* `assisted living`
* `broadband`
* `buses`
* `charter school`
* `coal power`
* `combined port authority`
* `community centre`
* `community college`
* `continuing care retirement community`
* `correctional facilities`
* `courts`
* `critical access hospital`
* `development district`
* `electrical infrastructure`
* `ferries`
* `fire`
* `flood control`
* `gas infrastructure`
* `gas power`
* `gas prepay`
* `health system`
* `hospitality`
* `independent living`
* `industrial development`
* `irrigation`
* `library`
* `local hfa multi-family housing`
* `local hfa single family housing`
* `local standalone multi-family housing`
* `local standalone single family housing`
* `military housing`
* `miscellaneous`
* `museum`
* `non-toll bridges`
* `non-toll roads`
* `nuclear power`
* `nursing home`
* `office buildings`
* `parking facilities`
* `parks`
* `police`
* `pollution control`
* `pre-school and daycare`
* `private college`
* `public buildings`
* `public college`
* `public housing`
* `public school district`
* `regional toll bridges`
* `regional toll roads`
* `sewer`
* `shopping centres`
* `solar power`
* `specialty hospital`
* `stadium`
* `standalone hospital`
* `standalone port`
* `standalone public school`
* `state hfa multi-family housing`
* `state hfa single family housing`
* `state toll bridges`
* `state toll roads`
* `storm water`
* `student housing`
* `student loan`
* `telephone`
* `trains`
* `tribal`
* `waste removal`
* `water`
* `wind power`

## Using the Taxonomy

### Understanding Bond Data

When you retrieve bond data from the muni\_reference endpoint, you'll see all three taxonomy levels populated:

```json theme={"theme":{"light":"catppuccin-latte","dark":"github-dark-high-contrast"}}
{
  "uses_of_proceeds": ["public college"],
  "use_categories": ["higher education"],
  "use_sectors": ["education"]
}
```

This tells you that the bond is used for a public college (specific), which is a type of higher education (middle level), within the education sector (broad).