Plain-English definitions for the words nobody explains.
Every term used across the guides and calculators, defined in one sentence (or two if it earns it). Where a term has its own guide, the definition links there. Browsing by topic instead? See the subject index. Looking for the visualizations? See the chart gallery.
Foundations
- Emergency fund
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3–6 months of essential expenses in cash savings. The buffer that stops every other plan from unraveling.
See the emergency fund guide and the sizing calculator.
- Order of operations
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The sequence for what to do with each dollar: deductibles → match → debt → fund → Roth → 15% → goals → debt → wealth.
See the order of operations guide and walkthrough.
- Sinking fund
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A dedicated savings bucket for a specific upcoming expense — a car, holiday gifts, an annual insurance premium — funded monthly so the cash is already there when the bill arrives. Distinct from an emergency fund, which is for the unforeseeable.
- Zero-based budgeting
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Assign every dollar of income a job — spending, saving, giving, or debt payoff — until nothing is left unassigned. The leftover is what drifts; naming it is what makes a budget stick.
See the budget builder.
Income
- Earned income
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Compensation for work — W-2 wages or 1099 self-employment income. Required to contribute to an IRA. Allowance, gift money, and investment income don't count.
- Gross income
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Total earnings before taxes, FICA, and any deductions. The number on your offer letter. 401(k) deferral percentages run on this.
- Net income / Take-home
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What lands in your bank after taxes and deductions. Useful for budgeting; misleading for retirement-savings percentages (always anchor those on gross).
- AGI
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Adjusted Gross Income. Gross income minus certain deductions (Traditional 401(k) contributions, HSA, etc.). Used to determine eligibility for many tax breaks.
- MAGI
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Modified AGI. AGI with certain items added back. Used for Roth IRA income limits and ACA subsidies.
Tax timing
- Pre-tax
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Money contributed before income tax is deducted. Lowers taxable income today; you pay tax later when you withdraw.
- After-tax (Roth)
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Money contributed after income tax. No upfront deduction; growth and qualified withdrawals are tax-free.
- Tax-advantaged
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Account or contribution that receives preferential federal-tax treatment — pre-tax in (401(k), Traditional IRA), tax-free growth (529, HSA, Roth), or both. Umbrella term for the wrappers that beat a plain brokerage on after-tax math.
- Tax-deferred
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Investments grow without annual taxation. Tax is paid on withdrawal. Traditional 401(k)/IRA work this way.
- Tax-free
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Investments grow with no annual tax AND withdrawals are tax-free. Roth 401(k)/IRA and HSA (for medical) work this way.
- Marginal tax bracket
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The rate on your last dollar of income. Different from your "effective" (average) tax rate, which is lower.
See the tax bracket explorer.
- Effective tax rate
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Total federal income tax owed divided by income. "Of gross" answers what fraction of your paycheck goes to tax; "of taxable income" matches the IRS form. Both are always lower than your top marginal bracket.
See the tax bracket explorer — it shows both.
- Taxable income
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Gross income minus deductions (standard or itemized). The base your federal brackets apply to — never your full salary.
- Standard deduction
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A fixed amount subtracted from gross income before brackets apply. Set by filing status; most people take it instead of itemizing.
- FICA
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Federal Insurance Contributions Act — payroll tax for Social Security (6.2%) and Medicare (1.45%). Comes out of every W-2 paycheck, before federal income tax.
Accounts
- 401(k)
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Employer-sponsored retirement account funded with pre-tax (Traditional) or after-tax (Roth) payroll deferrals.
See the 401(k) guide.
- 403(b)
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Same idea as a 401(k), but for public schools, hospitals, and certain non-profits. Same contribution limits.
- IRA
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Individual Retirement Account. Opened by you, not your employer. Lower limits than a 401(k) but more investment flexibility.
See the IRA guide.
- Roth IRA
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IRA funded with after-tax dollars. Growth and qualified withdrawals are tax-free. Income limits apply.
- Custodial Roth IRA
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A Roth IRA opened for a minor by a parent or guardian acting as custodian. Same rules as a regular Roth — including the earned-income requirement — until the minor reaches the age of majority.
See the teen Roth IRA guide.
- Traditional IRA
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IRA funded with pre-tax dollars (if eligible). Withdrawals taxed as ordinary income in retirement.
- HSA
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Health Savings Account. Triple tax-advantaged: pre-tax in, tax-free growth, tax-free out for medical. Requires an HDHP.
See the HSA guide.
- HDHP
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High-Deductible Health Plan. Required to be eligible to contribute to an HSA.
- 529 Plan
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State-sponsored education savings account. Tax-free growth, tax-free withdrawals for qualified education.
See the 529 guide.
- Brokerage account
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Taxable investment account with no contribution limits and full liquidity. Long-term gains taxed at lower rates.
- High-yield savings
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An online savings account paying a market interest rate — FDIC-insured, fully liquid, and built to keep pace with inflation rather than beat it.
Investing
- Index fund
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A fund that holds every stock in an index (e.g., S&P 500), proportionally. Low fees, broad diversification, no manager picking stocks.
- Money-market fund
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A low-risk fund of short-term debt held inside a brokerage account — pays a money-market yield but, unlike a bank account, is not FDIC-insured.
- ETF
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Exchange-Traded Fund. Like a mutual fund but trades like a stock. Most index funds today are ETFs.
- Target-date fund
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A fund that auto-rebalances from stocks toward bonds as you approach a retirement year (e.g., Target Date 2055). Good default for set-and-forget investors.
- Expense ratio
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Annual fee charged by a fund, as a % of assets. Anything above 0.20% is suspect; 0.05% or less is excellent.
- Compound growth
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Earnings on earnings. Each year your previous gains also generate gains. Calculator: compound growth.
- Wealth multiplier
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What $1 saved today grows into at age 65. Drops off a cliff with age — $1 at 20 ≈ $88; $1 at 40 ≈ $12 (10% nominal, monthly compounding).
See the mental models guide and compound growth calculator.
- Dollar Cost Averaging (DCA)
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Investing a fixed amount on a regular schedule, regardless of price. Default if you contribute every paycheck.
See the DCA guide.
- Asset allocation
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How your portfolio is split between stocks, bonds, and other asset classes. The single biggest driver of long-term returns.
- Glide path
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The pre-set schedule by which a target-date fund shifts from stocks toward bonds as it approaches its target year. The reason a Target Date 2055 fund holds a different mix today than it will in 2050.
- Basis points
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One basis point equals 0.01% — one hundredth of a percent. Used for small fee differences and rate moves. A fund charging 5 bps costs 0.05%; a Fed rate cut "of 25 bps" is 0.25%.
Debt
- APR
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Annual Percentage Rate. The yearly interest rate on a debt. Above ~7%, prioritize payoff over investing extra.
See the debt payoff guide for the three-tier framing.
- Snowball method
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Pay off smallest debt first. Behaviorally optimal — each finished debt builds momentum.
See the debt payoff guide and payoff calculator.
- Avalanche method
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Pay off highest-APR debt first. Mathematically optimal — minimizes total interest.
See the debt payoff guide and payoff calculator.
- Amortization
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How a loan payment splits between interest and principal. Early payments are mostly interest; late payments are mostly principal.
See the debt payoff guide (for consolidation context), the mortgages guide, and the mortgage payoff calculator.
- 20/3/8 rule
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Money Guy Show car-buying constraint: 20% down, 3-year max loan, and a monthly car payment under 8% of gross income. The 8% cap is the binding one and applies to the payment itself, not total transportation costs.
See the mental models guide.
- Prime
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The base interest rate U.S. banks charge their most creditworthy borrowers — moves with the Fed's target rate. Most variable-rate consumer debt (credit cards, HELOCs, private student loans) prices at "Prime + a margin."
- SAVE plan
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Saving on a Valuable Education — a federal income-driven student-loan repayment plan introduced in 2023; currently paused by court injunction, with payments and forgiveness eligibility on hold. Verify current status at studentaid.gov before relying on it.
Housing
- Mortgage
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A loan secured by real estate, typically thirty years, repaid in monthly principal-and-interest installments. The largest single debt most households ever take on.
See the mortgages guide.
- ARM
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Adjustable-Rate Mortgage. Fixed rate for an introductory period (commonly 5, 7, or 10 years), then resets to a market-tied rate at each adjustment.
See the mortgages guide.
- PMI
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Private Mortgage Insurance. Required on conventional loans when the down payment is under 20%; protects the lender, not the borrower. Removable at 80% LTV by request, automatic at 78%.
See the mortgages guide.
- Points
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Upfront fees paid at closing to lower the interest rate. One point typically equals 1% of the loan amount and lowers the rate by about 0.25 points. Worth it only if you keep the loan past the break-even month.
See the mortgages guide.
- Escrow
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A servicer-held account that collects monthly portions of property taxes and homeowners insurance, then pays the bills on your behalf once a year.
See the mortgages guide.
- PITI
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Principal, Interest, Taxes, Insurance — the four pieces bundled into a typical monthly mortgage payment.
See the mortgages guide and mortgage payoff calculator.
- LTV
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Loan-to-Value ratio. The loan balance divided by the home value. Above 80% triggers PMI on conventional loans; at 78% PMI auto-cancels.
See the mortgages guide.
- HOA
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Homeowners Association. Monthly or annual dues on condos, townhomes, and many planned communities. Not part of the loan but part of the true monthly housing cost.
- HELOC
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Home Equity Line of Credit. A revolving loan secured by your home's equity, priced at Prime + a margin. Cheaper than a credit card but still debt; banks can freeze unused capacity in downturns, and since 2018 federal tax reform the interest is only deductible when proceeds go to buying or improving the same home.
Home buying
- Pre-qualification
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A rough estimate of what a lender might lend you, based on numbers you provide without verification. Quick, free, and not very binding — sellers treat it as informal interest, not proof you can close.
- Pre-approval
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A conditional commitment from a lender after verifying your income, assets, and credit. Comes with a letter sellers take seriously. Stronger than pre-qualification, but still subject to underwriting once you have a specific property.
- DTI
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Debt-to-Income ratio. Your total monthly debt payments divided by gross monthly income. Most conventional lenders cap the total around 43%; FHA can stretch higher. Determines how much loan you qualify for.
- Closing costs
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Fees charged at signing — origination, title, recording, transfer tax, escrow setup, and more. Typically 2–5% of the loan amount. Separate from the down payment.
- Cash to close
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The total funds the buyer must bring to closing: down payment + closing costs + prepaids, minus any credits or earnest money already deposited. The single most important number on the closing disclosure.
- Earnest money
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A deposit the buyer puts up when an offer is accepted, typically 1–3% of the purchase price. Held in escrow during contract; credited toward closing if the deal closes, forfeited if the buyer backs out without a covered contingency.
- Appraisal
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A licensed appraiser's independent estimate of the property's market value, ordered by the lender. If it comes in below the contract price, the lender will only lend against the appraised value — the buyer brings extra cash, the seller drops the price, or the deal falls apart.
- Contingency
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A condition in a purchase contract that lets the buyer back out without forfeiting earnest money. Common ones: financing, inspection, appraisal, and home-sale contingencies. Waiving contingencies makes an offer stronger and riskier.
- Loan estimate
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A federally required 3-page document a lender must provide within 3 business days of a complete application. Standardized format makes lender-to-lender comparisons direct — compare loan estimates, not headline rates.
- Closing disclosure
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A federally required 5-page document the lender must provide at least 3 business days before closing. Final version of the loan estimate with the actual numbers. Sign nothing until you've compared it line-by-line to the loan estimate you accepted.
- Title insurance
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Two policies sold at closing: the lender's policy (required, protects the lender) and the owner's policy (optional, protects you against ownership-claim disputes). The owner's policy is one-time at closing and lasts as long as you own the home.
- Rate lock
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A lender's guarantee to hold a quoted rate for a set period (typically 30–60 days) while underwriting completes. Without a lock, the rate can drift with the market and your deal's economics change.
- Conforming loan
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A mortgage that meets Fannie Mae and Freddie Mac's size and quality limits ($832,750 baseline for 2026; higher in expensive counties). Conforming loans get the best rates because Fannie and Freddie will buy them from the lender.
- Conventional loan
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A mortgage not backed by a government program (FHA, VA, USDA). Most conventional loans are conforming. Typically requires 5–20% down and decent credit; PMI applies under 20% down.
- Underwriting
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The lender's risk assessment — verifying income, assets, credit, property value, and title. Where pre-approval turns into a final approval (or a "conditional" approval pending specific documents). The slowest stretch of a closing timeline.
- Comparable
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Often shortened to "comp." A recent sale of a similar property used to support an appraisal or pricing decision. Appraisers usually need three comps closed within the last 6 months and within a mile of the subject property.
- Seller concessions
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An amount the seller agrees to pay toward the buyer's closing costs as part of the negotiated price. Capped by loan type (3% for conventional with under 10% down, 6% for FHA). Functionally a hidden price reduction structured as a closing-cost credit.
Retirement
- Employer match
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Money your employer contributes to your 401(k), often as a % of what you contribute. Always capture the full match — it's a 50–100% guaranteed return.
- Vesting
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How long you must work before employer-contributed funds are yours to keep. Common: cliff (4 yrs all-or-nothing) or graded (20% per year).
- RMD
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Required Minimum Distribution. Mandatory annual withdrawal from Traditional 401(k)/IRA starting at age 73 (rising to 75). Roth doesn't have RMDs in your lifetime.
- FRA
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Full Retirement Age for Social Security. 66 to 67 depending on birth year. The age at which you get 100% of your earned benefit.
See the Social Security guide.
- 4% rule
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Heuristic that a 4% initial withdrawal — adjusted for inflation each year — has historically lasted 30 years. Useful starting point, not a guarantee.
- Rule of 25
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The 4% rule read backwards: target nest egg ≈ 25 × annual spending. The single multiplication that turns a target lifestyle into a portfolio number.
See the mental models guide.
- Income multiple
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Retirement-savings benchmark expressed as multiples of your annual income — e.g. 1× by 30, 3× by 40, 6× by 50, ~10× by retirement (Fidelity, T. Rowe Price, JPMorgan).
See the mental models guide.
- Sequence of returns
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The risk that a bad market in your first decade of retirement drains your portfolio faster than a bad market later would. A few bad early years are harder to recover from than a few bad late years.
Insurance
- Cash value
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The savings sub-account inside a permanent life policy (e.g. whole life), funded only after each month's insurance and commission costs come out. Grows slowly; reaching it means borrowing against your own policy.
- Term life insurance
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Pays a death benefit if you die during a fixed term. Cheap, simple. The right kind of life insurance for almost everyone who needs life insurance.
- Whole life insurance
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Permanent life insurance with a cash-value component. Almost always overpriced for what it does. Skip.
See the insurance guide.
- Long-term disability (LTD)
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Replaces ~60% of gross income if you can't work due to illness or injury. The most overlooked insurance for working-age adults.
- Deductible
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The amount you pay out of pocket before insurance starts paying. Hold cash equal to your biggest deductible (usually health) — it's the buffer between a bad week and a bad year.
- LIRP
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Life Insurance Retirement Plan. Marketing language for an indexed universal life (IUL) policy pitched as a tax-advantaged retirement wrapper; fees and crediting caps usually leave term life plus a brokerage account ahead.
- Participation rate
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In an indexed universal life (IUL) policy, the share of the linked index's gain credited to your cash value before the cap applies — often 60–100%, set by the insurer and adjustable later.