29 C.F.R. § 825.500
(c) Covered employers who have eligible employees must maintain records that must disclose the following:
(f) If FMLA-eligible employees are not subject to FLSA's recordkeeping regulations for purposes of minimum wage or overtime compliance (i.e., not covered by or exempt from FLSA), an employer need not keep a record of actual hours worked (as otherwise required under FLSA, 29 CFR 516.2(a)(7)), provided that:
(g) Records and documents relating to certifications, recertifications or medical histories of employees or employees' family members, created for purposes of FMLA, shall be maintained as confidential medical records in separate files/records from the usual personnel files. If the Genetic Information Nondiscrimination Act of 2008 (GINA) is applicable, records and documents created for purposes of FMLA containing family medical history or genetic information as defined in GINA shall be maintained in accordance with the confidentiality requirements of Title II of GINA (see 29 CFR 1635.9), which permit such information to be disclosed consistent with the requirements of FMLA. If the ADA, as amended, is also applicable, such records shall be maintained in conformance with ADA confidentiality requirements (see 29 CFR 1630.14(c)(1)), except that: