# CDX: Radioimmunoassay, Total Thyroxine

- Device class: 2; regulation: 21 CFR 862.1700; FDA's rule: 510(k) exempt
- FDA decisions: 121
- Recalls: 0 (0 Class I)
- Data: FDA decisions to Oct 25, 2026; recalls to Oct 12, 2026; MAUDE to Sep 30, 2026

## Decisions per year (last 10)
- 1987: 5
- 1988: 3
- 1989: 1
- 1990: 3
- 1991: 4
- 1992: 4
- 1993: 6
- 1994: 1
- 1995: 2
- 1996: 1

## Most-cited predicates
- K943416: Delfia Neonatal Thyroxine Kit (1995), cited by 1
- K905532: Ciba Corning Acs T4 Immunoassay (1991), cited by 1

Source page: https://510kreport.com/product-code/CDX
Data by year (CSV): https://510kreport.com/product-code/CDX.csv