Claim Reserve Estimation Workbook™ (CREW™) is a proprietary tool available to Milliman clients that estimates incurred but not reported (IBNR) medical claim liabilities. Based in Microsoft Excel®, CREW is a convenient template that performs a series of actuarial-based claim reserve calculations using an organization's actual claims data.

Clients who lease CREW receive more than a software package. Milliman experts support CREW with a comprehensive half-day training session to make sure new users have a clear understanding of the actuarial principles underlying the program.

Patterns, projections, and estimates

CREW develops monthly claim lag patterns and uses these patterns to develop incurred claim estimates. CREW also develops incurred claim estimates based on historical cost projections. The final estimates are based on a blending of these two methods. The IBNR reserve estimate is the incurred claim estimate less paid claims to date.

CREW's flexibility allows the user to review and select claim lag ratios, lag credibility factors, and projected trend and seasonality rates. For large claims, CREW allows the user to mitigate impacts in two ways; eliminating the effect on completion factor development and dampening the effect on future projections.

CREW permits the development of separate IBNR estimates concurrently for as many as six different categories (e.g., hospital inpatient, hospital outpatient, specialty physician, or line of business). This flexibility permits the user to recognize claims submission and processing pattern variations by service type or line of business, and to perform separate calculations to develop total IBNR estimates. The user can then easily test the sensitivity of different sets of assumptions on these resulting IBNR estimates.