Should we implement laws as written in legislation or the US Code?

[MaxGhenis]

We generally cite the US Code. However, we implemented the Emergency Broadband Benefit before it became available in the US Code, so we cited the legislation instead, and wrote the code as described in the law. The US Code writes EBB slightly differently than the legislation. How should we implement it?

Specifically, the Consolidated Appropriations Act, 2021 says of EBB's relationship to Lifeline:

The term ‘‘eligible household’’ means, regardless of whether the household or any member of the household receives support under subpart E of part 54 of title 47, Code of Federal Regulations (or any successor regulation), and regardless of whether any member of the household has any past or present arrearages with a broadband provider, a household in which—
(A) at least one member of the household meets the qualifications in subsection (a) or (b) of section 54.409 of title 47, Code of Federal Regulations (or any successor regulation);

"subpart E of part 54 of title 47, Code of Federal Regulations" refers to Lifeline, and "subsection (a) or (b) of section 54.409 of title 47" refers to Lifeline eligibility.

However, 47 CFR § 54.1605, which defines EBB eligibility, does so specifically: 135% of the poverty line or categorical eligibility, rather than pointing to Lifeline eligibility.

When I first added EBB to openfisca-us, I made is_lifeline_eligible a categorical eligibility "program". Now that it's written in CFR separately, should we rewrite it to have its own parameters (FPL limit and categorical eligibility), separately from Lifeline?