Want the official version? EBSA's Fact Sheet is succinct on its statements on the scope of service providers, and the timing:

Information required to be disclosed by a covered service provider must be furnished in writing to a responsible plan fiduciary for the covered plan. The rule does not require a formal written contract delineating the disclosure obligations.
CSPs must describe the services to be provided and all direct and indirect compensation to be received by a CSP, its affiliates, or subcontractors.
"Direct compensation" is compensation received directly from the covered plan. "Indirect compensation" generally is compensation received from any source other than the plan sponsor, the CSP, an affiliate, or subcontractor.
In order to enable a responsible plan fiduciary to assess potential conflicts of interest, CSPs who disclose "indirect compensation" also must describe the arrangement between the payer and CSP pursuant to which indirect compensation is paid. CSPs must identify the sources for indirect compensation, plus services to which such compensation relates.
Compensation disclosures by CSPs will include allocations of compensation made among related parties (i.e., among a CSP's affiliates or subcontractors) when such allocations occur as a result of charges made against a plan's investment or are set on a transaction basis.
CSPs must disclose whether they are providing recordkeeping services and the compensation attributable to such services, even when no explicit charge for recordkeeping is identified as part of the service "package" or contract.

Instant Insights /

5 fee disclosure steps for plan sponsors