Older adults often have access to several income streams, from Social Security to 401(k)s.Credit: Halfpoint Images / Getty Images Key Takeaways It's preferable to fund your retirement via multiple income streams, rather than just one. This makes your finances more stable. Guaranteed sources like Social Security and pensions can fund predictable expenses. Part-time work and investments can fill in the gaps. Other options include annuities and reverse mortgages, though both come with major downsides. ...