Program of All-Inclusive Care for the Elderly Plus Act or the PACE Plus Act This bill modifies requirements and establishes programs regarding Programs of All-Inclusive Care for the Elderly (PACE). PACE is a program under Medicare and Medicaid that provides in-home and community services for certain individuals as an alternative to nursing home care. The bill allows Medicare beneficiaries to enroll in a PACE program at any time and provides states with the option to allow Medicaid beneficiaries to do the same. Entities may also apply to become PACE providers at any time, upon specified assurances relating to staffing and other requirements. States that provide Medicaid coverage of long-term care may also choose to expand PACE eligibility for Medicaid beneficiaries who are unable to perform at least two activities of daily living and who meet other specified criteria. Additionally, the bill establishes and provides funds for grant programs for (1) public or nonprofit PACE providers in rural or underserved urban areas for planning, administrative, capital, and other expenses that are necessary for site development; and (2) states that do not have PACE providers for expenses deemed necessary for program establishment. The bill also allows the Center for Medicare and Medicaid Innovation to test a model for expanded PACE eligibility that targets high-need and high-cost populations.