---
kind: "section"
citation: "42 C.F.R. § 81.21"
title: "42"
number: "81.21"
heading: "Cancers requiring the use of NIOSH-IREP."
url: "https://uscodex.org/cfr/42/81.21"
---

# §81.21. Cancers requiring the use of NIOSH-IREP.

- (a) DOL will calculate probability of causation for all cancers using NIOSH-IREP.
- (b) Carcinoma in situ (ICD-10-CM codes D00-D09), neoplasms of uncertain behavior (ICD-10-CM codes D37-D44 and D48), and neoplasms of unspecified nature (ICD-10-CM code D49) are assumed to be malignant, for purposes of estimating probability of causation.
- (c) All secondary and unspecified cancers of the lymph node (ICD-10-CM codes C77 and C7B.01) shall be considered secondary cancers (cancers resulting from metastasis of cancer from a primary site). For claims identifying cancers of the lymph node, Table 1 in [§ 81.23(a)](/cfr/42/81.23.md?p=a) provides guidance for assigning a primary site and calculating probability of causation using NIOSH-IREP.

## Notes

### Amendments

[84 FR 37590, Aug. 1, 2019]

### Authority

Authority: 42 U.S.C. 7384n(c); E.O. 13179, 65 FR 77487, 3 CFR, 2000 Comp., p. 321.

### Source

Source: 67 FR 22309, May 2, 2002, unless otherwise noted.

### Amendments

[84 FR 37590, Aug. 1, 2019]