[[Actuarial Notes Wiki|Wiki]] / [[Exam 5 (CAS)]] / **Policy Year**
## Definition
==Policy Year== Policy year is a data organization method where all premiums, losses, and expenses are grouped by the year in which the policy became effective, tracked throughout the entire policy period.
## Key Features
### Complete Policy View
- Includes all transactions for policies effective in a given year
- Follows policies from inception through expiration and claim settlement
- Provides most complete profitability picture
### Development Period
Policy year data requires the longest development period:
- Policy term (typically 12 months)
- Plus claim settlement period (varies by line)
- Long-tail lines may take 10+ years to fully develop
## Uses
**Profitability Analysis**
- True underwriting profitability
- Management performance evaluation
- Line of business assessment
**Experience Rating**
- Individual risk evaluation
- Retrospective rating calculations
- Large deductible programs
## Advantages
1. Matches premium with corresponding losses
2. Best measure of underwriting profitability
3. Useful for homogeneous exposure groups
4. Clear beginning and end of exposure period
## Disadvantages
1. Longest development period
2. Complex data requirements
3. Delayed availability for rate indications
4. Requires sophisticated tracking systems
## Example
```
Policy effective 7/1/2024 (12-month term):
Policy Year 2024 includes:
- Full premium for 7/1/2024 - 6/30/2025 policy
- All losses occurring 7/1/2024 - 6/30/2025
- Development continues until all claims settled
Development timeline:
- 7/1/2024: Policy effective
- 6/30/2025: Policy expires
- 2026-2030+: Claims settle
- Full maturity: When all claims closed
```
## Conversion Between Methods
Policy year can be converted to accident year:
- 12-month policies: PY → 2 AY (partial overlap)
- Parallelogram method used for conversion
## Related Concepts
- [[Ratemaking Data Organization]]
- [[Accident Year]]
- [[Calendar Year]]
- [[Experience Rating]]
## References
- Werner & Modlin, Chapter 3