I think it could make sense to shift your stock allocation from riskier stocks as you near retirement. However, I plan on keeping my stock allocation the same before and after retirement. But if I was going to shift away from riskier assets, here's an example of how I would do it.
Here's my current stock allocation:
35% VTI (Total US Stock)
35% VXF (Extended Market)
15% VXUS (International Stock)
15% VSS (International Small-Cap)
Lets say as I neared retirement, I wanted to have less exposure to small/mid-cap companies while keeping my domestic/foreign allocation at 70%/30%. I would come up with a plan and put it in my
IPS. So I would maybe start 15 years before retirement and begin shifting 1% of VXF to VTI and 1% of VSS to VXUS. Then by the time I retired I would be at 70% VTI and 30% VXUS in my stock allocation.
This shift of your stock allocation could be going on while you are also lowering your overall stock allocation to purchase more bonds.