Protecting Access to Lifesaving Screenings Act of 2021 or the PALS Act This bill makes a series of changes relating to health insurance coverage of screening mammography. Specifically, the bill requires that any provision of law referring to current recommendations of the U.S. Preventive Services Task Force (USPSTF) with respect to breast cancer screening mammography be administered as if (1) the provision referred to USPSTF recommendations last issued before 2009; and (2) those recommendations applied to any screening mammography modality, including any digital modality of such a procedure. This requirement shall also apply to the Veterans Health Administration's policy on mammography screening for veterans. In addition, the bill preserves Medicare coverage for screening mammography, without a requirement for coinsurance, and expands the definition of screening mammography to include any digital modality of such a procedure. Further, the Centers for Medicare & Medicaid Services may not decrease the frequency with which screening mammography may be paid by Medicare for a woman over 39 years of age. In 2009, the USPSTF updated its guidelines to recommend against routine screening mammography for women between 40 to 49 years of age and to recommend biennial, instead of annual, screening mammography for most women between 50 to 74 years of age. In 2015, through the appropriations process, a three-year moratorium was placed on implementing the guidelines; the moratorium was subsequently renewed until January 1, 2023.