We make big financial decisions—about investing, selling a home and even choosing a health care plan—all the time. But we don’t always ask ourselves, How will this affect my taxes? Here are five situations in which remembering to consider the tax consequences—and possibly adjusting your strategy—could save you a lot of money.

Most people are aware of the interest deduction available to homeowners on up to $750,000 in mortgage debt. But did you know that when you sell your primary residence you could take advantage of a capital gains tax exclusion on the first $250,000—$500,000 if you’re married and file jointly—of gain?

The catch is that you and your spouse must have lived in the house for at least two of the past five years. Generally, you're not eligible for the exclusion if you excluded the gain from the sale of another home during the two-year period prior to the sale of your home. Still, it’s worth keeping in mind when you’re considering selling your home: With the maximum capital gains tax rate at 20 percent (plus a potential 3.8% net investment income tax), that exclusion could save you more than $100,000. (Remember to keep an eye on changes to the tax rules from year to year.)

When your employer’s enrollment period comes around every year, it’s worth checking to see if it offers a qualifying high-deductible health plan. When you enroll in a high-deductible health plan, you may be eligible to contribute to a health savings account (HSA). Your contributions to an HSA are tax deductible (or may be made by pre-tax salary deductions if allowed by your employer), and earnings and withdrawals for qualified medical expenses are federal income tax free.

There are many reasons you might want to consider selling an investment. Before you do, keep in mind there may be tax consequences when you sell investments to realize gains—but not all investment-related income is taxed at the same rate. For example, bond interest and dividends from real estate investment trusts (REITs) are often taxed as ordinary income, at rates as high as 37 percent (plus a potential 3.8% net investment income tax). And qualified dividends and profits on the sale of investments owned for more than a year are eligible for long-term capital gains rates, which are generally capped at 20 percent for most taxpayers (plus a potential 3.8% net investment income tax).

When you get a new job and participate in your retirement plan, you may have a choice between traditional 401(k) contributions and Roth 401(k) contributions. Traditional 401(k) contributions are made on a pre-tax basis, giving you immediate savings by reducing your federal taxable income. In addition, investment income in your account is not subject to federal taxes until money is taken out at retirement, at which time it’s taxed as federal ordinary income. Roth 401(k) contributions are made on an after-tax basis, but qualified withdrawals starting at age 59½ are potentially federal income tax free.

Choosing to set aside money for your children’s education in a tax-advantaged 529 college savings plan is one of the easiest financial decisions you’ll ever make. Withdrawals, including any earnings, are federal—and usually state—income tax free when used for qualified educational expenses, including college expenses, private elementary or secondary school (state tax treatment may vary). Each 529 plan has different features, investment options and expenses, so make sure you shop around for the right plan for your situation.