29 C.F.R. § 4010.6

(a) General. (1) Current filers. A filer must submit the information specified in § 4010.7 (identifying information), § 4010.8 (plan actuarial information) and § 4010.9 (financial information) with respect to each member of the filer's controlled group and each plan maintained by any member of the controlled group, and any other information relating to the information specified in §§ 4010.7 through 4010.9, as specified in the instructions on the PBGC's website.

(b) Additional information. By written notification, the PBGC may require any filer to submit additional actuarial or financial information that is necessary to determine plan assets and liabilities for any period through the end of the filer's information year, or the financial status of a filer for any period through the end of the filer's information year (including information on exempt entities and exempt plans). The information must be submitted within ten days after the date of the written notification or by a different time specified therein.

(c) Previous submissions. If any required information has been previously submitted to the PBGC, a filer may incorporate this information into the required submission by referring to the previous submission.