Series and Classes/Contracts Information:
| Existing | |||
| Status | Name | Ticker Symbol | |
| CIK 0000822632 | |||
| Series S000027022 | William Blair Low Duration Fund | ||
| Class/Contract C000081288 | Class N | WBLNX | |
| Class/Contract C000081289 | Class I | WBLIX | |
| Class/Contract C000081290 | Class R6 | WBLJX | |
IRS No.: 000000000 | Fiscal Year End: 1231
Type: NPORT-P | Act: 40 | File No.: 811-05344 | Film No.: 21964418