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

# US Federal Register

> Search filters and result fields of us_federal_register.

* **Dataset id:** `us_federal_register`
* **Jurisdiction:** US · Federal Register
* **Date field:** `publication_date`. The search's top-level `date_from` and `date_to` filter on it.
* **Access:** any API key.

## Filters

Send these under `filters.us_federal_register` in a [search](https://docs.rhizomeai.com/api-reference/v3/search.md) request. A filter not listed here, or a value of the wrong type, is a 400. The top-level `date_from` and `date_to` set `date_from` and `date_to` below, so give a date in one place only.

**document\_number** `string`

Exact Federal Register document number, e.g. '2026-19074'.

**doc\_type** `string`

Exact document type. 'Rule' is a final rule. Almost every 1994 document is 'Uncategorized Document' (untyped upstream) — for 1994 search by keywords and read the `action` column instead. Values: `Notice`, `Rule`, `Proposed Rule`, `Correction`, `Uncategorized Document`.

**title** `string`

Keyword match on the document title (BM25 tokenized). Example: 'premarket notification radiology'.

**agency** `string`

Exact phrase in the publishing agency names. Examples: 'Food and Drug Administration', 'Centers for Medicare & Medicaid Services', 'Health Care Finance Administration' (CMS before July 2001), 'Drug Enforcement Administration', 'Health and Human Services Department', 'National Institutes of Health', 'Inspector General' (HHS OIG). The abbreviations FDA, CMS, DEA, HCFA, HHS, NIH, CDC, OIG, SAMHSA, HRSA, AHRQ, ACF and IHS are accepted.

**docket\_id** `string`

Exact docket id (the regulations.gov docket), matched as a phrase, e.g. 'FDA-2025-P-5560'.

**cfr\_reference** `string`

Exact Code of Federal Regulations part the document touches, matched as a phrase, e.g. '21 CFR 892' (or just '314'). '21 CFR Part 892' and a section such as '21 CFR 892.2050' are read as the part. Populated on rules; NULL on most notices.

**date\_from** `string (date)`

Inclusive lower bound on publication date (YYYY-MM-DD).

**date\_to** `string (date)`

Inclusive upper bound on publication date (YYYY-MM-DD).

## Fields

Each result from this dataset has these in `fields`:

`abstract`, `action`, `agency_names`, `cfr_references`, `citation`, `comments_close_on`, `doc_type`, `docket_ids`, `document_number`, `effective_on`, `publication_date`, `regulation_id_numbers`, `title`, `topics`, `url`, `year`


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