---
kind: "section"
citation: "40 C.F.R. § 86.1802-01"
title: "40"
number: "86.1802-01"
heading: "Section numbering; construction."
url: "https://uscodex.org/cfr/40/86.1802-01"
---

# §86.1802-01. Section numbering; construction.

- (a) **Section numbering.** The model year of initial applicability is indicated by the section number. The two digits following the hyphen designate the first model year for which a section is applicable. The section continues to apply to subsequent model years unless a later model year section is adopted. Example: [Section 86.18xx-10](/cfr/40/86.18xx-10.md) applies to model year 2010 and later vehicles. If a [§ 86.18xx-17](/cfr/40/86.18xx-17.md) is promulgated, it would apply beginning with the 2017 model year; [§ 86.18xx-10](/cfr/40/86.18xx-10.md) would apply only to model years 2010 through 2016, except as specified in [§ 86.18xx-17](/cfr/40/86.18xx-17.md).
- (b) A section reference without a model year suffix refers to the section applicable for the appropriate model year.
- (c) If a regulation in this subpart references a section that has been superseded or no longer exists, this should be understood as a reference to the same section for the appropriate model year. For example, if a regulation in this subpart refers to [§ 86.1845-01](/cfr/40/86.1845-01.md), it should be taken as a reference to [§ 86.1845-04](/cfr/40/86.1845-04.md) or any later version of [§ 86.1845](/cfr/40/86.1845.md) that applies for the appropriate model year. However, this does not apply if the reference to a superseded section specifically states that the older provision applies instead of any updated provisions from the section in effect for the current model year; this occurs most often as part of the transition to new emission standards.

## Notes

### Amendments

[81 FR 73982, Oct. 25, 2016]

### Source

Source: 64 FR 23925, May 4, 1999, unless otherwise noted.

### Authority

Authority: 42 U.S.C. 7401-7671q.

### Amendments

[81 FR 73982, Oct. 25, 2016]