The article discusses a comparative analysis of full cost systems, "direct cost" and "standard cost". A comparative characteristic and features of using the accrual method and the cash basis method in management accounting are given. A practical example illustrates the advantages of using the cash method and the accrual method in calculating marginal income. The necessity of reflecting the marginal profit on a separate account 92 "Marginal profit (loss)" is substantiated and, in accordance with this, correspondence of accounts on the formation of marginal income using various methods is proposed. A new methodology for calculating CVP analysis indicators is proposed.