Objectives: Dutch health economic guidelines include a costing manual, which describes preferred research methodology for costing studies and reference prices to ensure high quality studies and comparability between study outcomes. This paper describes the most important revisions of the costing manual compared to the previous version. Methods: An online survey was sent out to potential users of the costing manual to identify topics for improvement. The costing manual was aligned with contemporary health economic guidelines. All methodology sections and parameter values needed for costing studies, particularly reference prices, were updated. An expert panel of health economists was consulted several times during the review process. The revised manual was reviewed by two members of the expert panel and by reviewers of the Dutch Health Care Institute. Results: The majority of survey respondents was satisfied with content and usability of the existing costing manual. Respondents recommended updating reference prices and adding some particular commonly needed reference prices. Costs categories were adjusted to the international standard: 1) costs within the health care sector; 2) patient and family costs; and 3) costs in other sectors. Reference prices were updated to reflect 2014 values. The methodology chapter was rewritten to match the requirements of the costing manual and preferences of the users. Reference prices for nursing days of specific wards, for diagnostic procedures and nurse practitioners were added. Conclusions: The usability of the costing manual was increased and parameter values were updated. The costing manual became integrated in the new health economic guidelines.@en