What a Flat-Fee Retirement Tax Engagement Actually Includes

The gap-year window, the years after leaving work but before Social Security and RMDs begin, is often the single highest-leverage stretch for tax planning in a person's financial life. A flat-fee planner's core deliverable is a multi-year Roth conversion plan that uses this window deliberately, filling lower tax brackets each year rather than letting pre-tax balances grow untouched until RMDs force large, less controllable distributions later.

IRMAA-tier projections are a related but distinct service. Medicare premiums are based on income from two years prior, so a single large distribution, even a well-intentioned Roth conversion, can trigger a surcharge that lasts a full year. A planner who models IRMAA thresholds alongside the conversion strategy avoids solving one problem by creating another. Withdrawal sequencing decides which account, taxable, pre-tax, or Roth, funds each year of spending, and interacts directly with that tax and IRMAA planning. Qualified charitable distributions, once RMDs begin, let a portion of the RMD go straight to charity without counting as taxable income, which only helps if coordinated with the rest of the plan rather than handled as an afterthought each December.

A genuinely comprehensive engagement runs the tax projection forward, not just for the current year but out toward age 90, since RMDs grow with age and a surviving spouse eventually files as a single taxpayer at compressed brackets, often the single biggest unplanned tax increase a retired household faces.

Retirement tax planning is unusual among financial planning disciplines in that many of its best moves involve intentionally moving money out of a managed account. Under a percentage-of-assets fee, that creates a quiet incentive problem: an advisor paid 1% of $2 million earns $20,000 a year, and recommending a $200,000 Roth conversion doesn't cost that advisor anything directly, but recommending it every year for five years to manage a client into a lower lifetime tax bill starts to work against the advisor's own revenue trajectory. Nobody has to act in bad faith for this to shape behavior; incentives shape defaults, and the default under AUM pricing tilts toward inertia. A flat fee removes that tilt entirely: the planner is paid to build and maintain a tax strategy, not to keep a balance intact.

The predictability of a flat fee matters as much as the incentive alignment. Retirement tax planning gets genuinely complicated once RMDs, IRMAA thresholds, Social Security taxation, and multi-bracket withdrawal sequencing are all interacting in the same projection. A flat fee is set once, based on complexity, and doesn't move just because the tax picture requires more modeling. Because the fee isn't tied to investment assets, flat-fee retirement tax planning also tends to be more integrated: withdrawal sequencing, Social Security claiming, Medicare and IRMAA management, and Roth conversion timing all interact with each other, and a planner paid for the whole picture has a reason to coordinate all of it.

Before hiring anyone, ask them to list what's actually included, not what the fee costs. The eight items above are the right checklist to compare against, and most firms will readily tell you which ones they don't do.

An annual update matters as much as the initial plan. Tax law, income, and market performance change every year, and a static plan built once and never revisited loses most of its value within a few years.

If you're currently paying a percentage of assets, ask directly what tax planning is included: an annual Roth conversion analysis, an IRMAA-tier projection, coordination with your CPA at tax time, or is the fee mostly paying for portfolio oversight with tax planning as an afterthought.

• Assuming 'tax planning' on a fee schedule means all eight deliverables are included, when it may mean only a general mention.
• Overlooking the surviving-spouse tax problem entirely, since it's often the largest unplanned tax increase a household faces.
• Treating IRMAA as a separate, unrelated issue from Roth conversions rather than something that has to be modeled alongside it.
• Confusing a flat-fee financial planner with a tax preparer. Most flat-fee planners coordinate with a CPA or EA rather than filing the return themselves, unless both functions sit under one roof.
• Assuming a flat fee costs more than AUM without running the actual numbers. On a $1.5M-$2M portfolio, a 1% AUM fee often exceeds what a comprehensive flat-fee retainer costs.