Should I contribute to my employer's 401(k) if I'm on an H-1B or L-1 and might not stay in the US?

Usually yes, at least up to the employer match, because the match is free money you'd otherwise leave behind. In 2025 you can defer up to $23,500 ($31,000 if 50+). Your visa status doesn't affect your right to participate. The worry immigrants raise is, "What if I leave?" Your 401(k) doesn't vanish, you keep it, can roll it to an IRA, leave it with the plan, or eventually take a distribution from abroad (with tax consequences). Vested employer contributions are yours; unvested ones are forfeited if you leave before vesting. Given the match and tax deferral, most people on work visas still come out ahead contributing. Capture at least the full match. See wealthserene.com/tools/retirement-planner.