It doesn't tell you what to do next. These do.
Before any plan, three government sources give you the facts. No account required for most. No sales pitch. Just your numbers.
Your official benefit estimate, full earnings history, and projected monthly payments at every claiming age from 62 to 70. This is the source of the number you enter in Runway. If you haven't looked at it recently, your estimate may be out of date — SSA recalculates based on your actual earnings each year.
Current contribution limits, catch-up rules by age, required minimum distribution tables, and early withdrawal rules. Updated every year. A useful reference if you want to check what you're allowed to set aside each year, or how catch-up contributions work once you're 50 or older.
Medicare coverage begins at 65 regardless of when you retire. If your model shows a work-optional age before 65, there is a healthcare coverage gap to account for. COBRA, marketplace plans, and spousal coverage are the three typical bridges — Medicare.gov outlines what you're bridging toward.
Three sources worth knowing. Two are written for professionals — rigorous, sometimes dense. One is written for everyone, and it may be the most useful tool on this page.
Michael Kitces is a CFP who has produced more rigorous ongoing research on retirement math than almost anyone else in the field. His work on withdrawal rates, sequence of return risk, and Social Security timing is cited by practicing financial planners everywhere — including in the Foundations page here. The site is written for advisors, not consumers. The articles are long and technical. But if you want to understand why Monte Carlo simulation matters more than average returns, or how sequence risk actually works in practice, this is where the serious work lives.
Wade Pfau is an economist and CFP whose work sits at the same level of rigor as Kitces — but written for the person doing the planning, not the advisor doing it for them. His Retirement Income Manifesto is a good starting point: a framework for thinking about retirement income that goes beyond "withdraw 4% and hope." His research on longevity risk — the possibility of outliving your assets — is the clearest treatment of the subject available outside academic journals.
Most Social Security guidance you'll find online is either oversimplified ("always wait until 70") or buried behind a financial advisor's sales process. Open Social Security is neither. It's a free, open-source calculator built by Mike Piper — a CPA and author — that models the mathematically highest-value claiming scenario for your specific inputs.
You enter your date of birth, your benefit at full retirement age, and — if married — the same for your spouse. The tool runs through every possible combination of claiming ages and tells you which maximizes your lifetime benefit in present value terms. It accounts for the spousal benefit, the survivor benefit, and the fact that delaying one spouse's claim often dramatically increases what the surviving spouse receives.
The tool is transparent about its assumptions and limitations. It doesn't sell anything. It doesn't ask for your email. The source code is public. It is, in the literal sense, just the math — which is exactly what it should be.
A model shows you the shape of the problem. A fiduciary advisor helps you solve it. The word "fiduciary" matters: it means they are legally required to act in your interest, not their own. Not all advisors are.
The National Association of Personal Financial Advisors. Every member is fee-only — they earn no commissions, no referral fees, no product sales. You pay them directly for advice. That structure eliminates the conflict of interest that exists when an advisor earns more by selling you certain products. Search by zip code.
Hourly and project-based fiduciary advice. No minimums, no ongoing retainer required. If you want a one-time plan review — someone to pressure-test what Runway is showing you — this is the right place to look. The model gave you the math. A Garrett advisor can tell you whether your assumptions are reasonable.
Search for Certified Financial Planners by name or location. CFPs are required to act in a fiduciary capacity when providing financial planning services and must meet ongoing education requirements. The CFP Board also maintains a public disciplinary history — worth checking before any engagement.