Can I leave my 401(k) with a former employer instead of rolling it over?

Often yes, if your vested balance exceeds the plan's small-balance threshold, which SECURE 2.0 raised to $7,000. Above that, the plan generally must let you stay. Balances between $1,000 and $7,000 may be automatically rolled into an IRA the plan chooses, and balances under $1,000 can be cashed out and mailed to you, triggering taxes.

Leaving it can make sense if the old plan has excellent low-cost funds or institutional share classes you cannot access elsewhere. The downsides are losing track of the account, dealing with a former employer's administrator, and fragmenting your retirement picture. If you leave it, keep your address current with the recordkeeper so you do not become one of the many owners of forgotten, unclaimed 401(k) accounts.