CMS has proposed its annual Notice of Benefit and Payment Parameters, which would apply to participation in Affordable Care Act (ACA) Health Insurance Marketplaces for 2018. In particular, the rule proposes revisions to the risk adjustment methodology to address, among other things:   risk associated with enrollees who are not enrolled for a full 12 months; use of prescription drug utilization data; transfers to better account for the risk of high-cost enrollees; use of more recent data for recalibration of risk adjustment models; and establishment of a discrepancy identification and administrative appeals process.  Numerous other policies are addressed in the proposed rule, including cost-sharing parameters; user fees; standardized health plan options; qualified health plan requirements; consumer assistance tools; network adequacy; the Small Business Health Options Program; stand-alone dental plans; fair health insurance premiums; guaranteed renewability; the medical loss ratio program; eligibility and enrollment; appeals; and oversight.  CMS will accept comments on the proposed rule until October 6, 2016.