---
title: RateTierFactorExtensions
summary: API reference for RateTierFactorExtensions.
status: draft
owner: Technical Writer
last_reviewed: 2026-07-31
library: SAIF.Business.Policy.Rating
reference_type: package
---
# RateTierFactorExtensions
Selects the first rate-tier factor that applies to a date and code. The module centralizes first-match selection of the effective rate-tier factor for a risk type and date.
## Purpose
- Selects the first rate-tier factor that applies to a date and code.
- The module centralizes first-match selection of the effective rate-tier factor for a risk type and date.
## Context
- Namespace: `SAIF.Business.Policy.Rating`
- Assembly/package: `SAIF.Business.Policy.Rating`
## Public members
| Member | Signature | Purpose |
| --- | --- | --- |
| AppliesTo | `Public Function AppliesTo(ByVal Target As IEnumerable(Of clsRateTierFactor), ByVal inRiskTypeCode As String, ByVal inDate As Date) As clsRateTierFactor` | Returns the first rate-tier factor whose risk type and effective or expiration window match the supplied code and date, implementing [BR-018](../../../../../business-rules.md#br-018-a-rate-tier-factor-applies-to-a-risk-type-code-on-a-date-when-the-code-matches-exactly-the-effective-date-is-on-or-before-the-date-and-the-expiration-date-is-either-null-dateminvalue-or-after-the-date). |
## Behavioral notes
- The extension returns the first factor row whose `IsApplicableTo` test matches the requested risk type and date.
## Constraints and usage notes
- Because the extension returns `FirstOrDefault`, callers must handle `Nothing` when no row covers the requested risk type and date.
## Sources
- `Business\SAIF.Business.Policy.Rating\clsRateTierFactorCollection.vb`