Corporate bonds offer higher income-yielding opportunities for investors willing to take on more risk than what comes with safer bets like Treasury bonds. While investing in individual corporate bonds can be difficult, bond funds offer an easy and efficient way to gain diversified exposure. These four funds are the best options, according to Morningstar analysts.To screen for the top-performing funds in this category, we looked for those with the best returns over the last one-, three-, and five-year periods. Offerings from Vanguard stood out, taking up two of the four spots.iShares 5-10 Year Investment Grade Corporate Bond ETF IGIBSchwab 5-10 Year Corporate Bond ETF SCHIVanguard Intermediate-Term Corporate Bond Index Fund VCITVanguard Intermediate-Term Investment Grade Fund VFIDXOver the past 12 months, the average fund in the corporate bond Morningstar Category returned 7.56%. On an annualized basis, corporate bond funds have climbed 5.70% over the past three years and gained 0.54% over the past five years. Meanwhile, the Morningstar US Core Bond Index has risen 7.11% over the past 12 months, gained 4.36% per year over the past three years, and lost 0.08% per year over the past five.Screening for the Top-Performing Corporate Bond FundsCorporate bond portfolios concentrate on investment-grade bonds issued by corporations in US dollars, which tend to have more credit risk than government or agency-backed bonds. These portfolios hold more than 65% of their assets in corporate debt, less than 40% of their assets in non-US debt, less than 35% in below-investment-grade debt, and durations that typically range between 75% and 150% of the three-year average of the effective duration of the Morningstar Core Bond Index.To find the best-performing corporate bond funds, we looked at returns from the past one, three, and five years using data in Morningstar Direct. We screened for open-end and exchange-traded funds in the top 33% of the category using their lowest-cost primary share classes for those periods. We also filtered for funds with a Morningstar Medalist Rating of Bronze, Silver, or Gold. We excluded funds with assets under $100 million and analyst coverage that was not 100%. This left four investments.Because the screen was created with the lowest-cost share class for each fund, some may be listed with share classes that are not accessible to individual investors outside of retirement plans, or they may be aimed at institutional investors and require large minimum investments. The individual investor versions of those funds may carry higher fees, reducing returns to shareholders. Medalist Ratings may differ among the share classes of a fund.iShares 5-10 Year Investment Grade Corporate Bond ETFMorningstar Medalist Rating: SilverMorningstar Rating: ★★★★Over the past 12 months, the iShares fund rose 9.40%, while the average fund in its category rose 7.56%. The fund, launched in January 2007, has climbed 6.81% over the past three years and 1.20% over the past five.IShares 5-10 Year Investment Grade Corporate Bond ETF offers a broad portfolio of intermediate-term corporate bonds for an attractive price. It may not be the most comprehensive corporate bond index fund, but its intermediate focus makes the fund a handy portfolio building block.The fund tracks the ICE BofA 5-10 Year US Corporate Index. The index captures investment-grade, US-dollar-denominated corporate bonds with five to 10 years remaining until maturity. Eligible bonds must have at least USD 250 million par amount outstanding. Market-value weighting and a wide scope produce a broad and diverse portfolio.The fund’s duration tends to be slightly shorter than that of the category average. Peers in the corporate-bond Morningstar Category tend to cast a wider net than the fund, with many capturing the full maturity spectrum. Average duration of peers increased during the low-interest-rate years after the 2008 financial crisis and the 2020 shock as companies favored longer-term borrowing. Part of the fund’s outperformance during the rates-driven meltdown in 2022 came from this duration gap versus the category average. This gap has since compressed to no more than a few months. But the fund’s duration tilt can sway its category-relative performance when interest rates move.Lan Anh Tran, analystSchwab 5-10 Year Corporate Bond ETFMorningstar Medalist Rating: SilverMorningstar Rating: ★★★★The $10.2 billion fund has climbed 9.26% over the past 12 months, outperforming the average fund in its category, which rose 7.56%. The Schwab fund, launched in October 2019, has climbed 6.58% over the past three years and 1.05% over the past five.The fund tracks the Bloomberg US 5-10 Year Corporate Bond Index, which holds investment-grade corporate bonds with between five and 10 years remaining until maturity. Eligible bonds must have a fixed coupon rate and at least USD 300 million outstanding face value. It excludes riskier types of bonds, such as contingent capital securities and bonds with equity features. The index weights selected bonds by their market value. The market does a decent job pricing these bonds in the vast and liquid investment-grade corporate bond market, so this is an efficient approach.The fund’s focus on intermediate-term bonds shortens its duration relative to the average category peer, as it excludes the longer end of the maturity spectrum. As of May 2025, its average duration of 6.1 years is shorter than that of the category average by a few months. This gap can widen when companies begin issuing longer-term debt. This was the case during the low-rate environment a few years ago as companies preferred to issue more long-term bonds, which lengthened the market’s average duration. The fund benefited from its shorter duration when rates increased in 2022, alongside other intermediate-focused corporate bond funds.The fund often takes less credit risk than its peers. Active managers have the flexibility to reach into junk bonds to incrementally improve their yields, while this fund cannot. Instead, this fund overweights A rated bonds by typically parking more than 40% of its assets here. The fund’s 50% stake in BBB rated bonds is in line with that of the category average and ensures the fund will still perform well when credit rallies, albeit to a lesser extent than more aggressive peers. In return, the fund should outperform peers when credit spreads widen.Lan Anh Tran, analystVanguard Intermediate-Term Corporate Bond Index FundMorningstar Medalist Rating: GoldMorningstar Rating: ★★★★Over the past 12 months, the Vanguard fund rose 9.22%, while the average fund in its category rose 7.56%. The fund, launched in November 2009, has climbed 6.57% over the past three years and 1.08% over the past five.Vanguard Intermediate-Term Corporate Bond offers an inexpensive and well-constructed portfolio of investment-grade corporate bonds set to mature in five to 10 years.The Bloomberg US 5-10 Year Corporate Bond Index, which underpins this fund, sweeps in investment-grade corporate bonds with five to 10 years remaining to maturity. The index excludes riskier types of bonds such as floating-rate notes, contingent capital securities, and bonds with equity features. Eligible bonds must also have at least USD 300 million outstanding face value, which increases the investability of the index. It weights bonds by their market value, which is an efficient and cost-effective approach to the vast and relatively liquid investment-grade bond market.The fund tends to overweight higher-quality bonds compared to its average Morningstar Category peer. It parked more than 40% of its assets in A rated bonds as of May 2025, 10 percentage points more than the category average. More flexible active category peers often take on a small position in high-yield bonds instead in their quest to add incremental value. Bypassing riskier bonds has helped this fund better protect against widening credit spreads during credit shocks.The fund remains a precise tool for investors targeting high-quality, intermediate-term corporate bonds. Its low fee should preserve its performance edge over the long run. The ETF share class has beaten the category average by 39 basis points between its 2009 inception and May 2025.Lan Anh Tran, analystVanguard Intermediate-Term Investment Grade FundMorningstar Medalist Rating: BronzeMorningstar Rating: ★★★★Over the past 12 months, the Vanguard fund rose 9.41%, while the average fund in its category rose 7.56%. The fund, launched in February 2001, has climbed 6.59% over the past three years and 1.17% over the past five.Vanguard Intermediate-Term Investment-Grade’s willingness to increase its credit risk combined with moderate duration positioning relative to most corporate bond Morningstar Category peers has proved competitive thus far but not yet compelling.The basic process here remains intact. The firm’s senior investment and taxable strategy committees shape macroeconomic views, setting broad risk parameters around duration, sector allocation, and credit outlook. Lead manager Arvind Narayanan and comanager Dan Shaykevich collaborate with investment-grade specialists and the risk team to allocate risk within guidelines and refine portfolio construction.The strategy’s credit profile began to shift a few months after Narayanan’s tenure began in late 2019. While the team keeps BBB exposure within 10 percentage points of its Bloomberg US Credit 5 to 10 Year Index, the fund increased its BBB weighting nearly threefold between the first quarters of 2020 and 2022, and that stake now typically accounts for about half of the portfolio’s assets, in line with the category median. Exposure to junk bonds also increased over the same period and has been modestly above the category median in recent years. Even if the fund maintains a relatively hefty stake in AAA debt, including US government bonds, the portfolio is now more sensitive to changes in option-adjusted credit spreads than in the past.Moderate interest rate sensitivity (as measured by duration) compared with most rivals remains a feature of the portfolio. At year-end 2024, for example, the fund’s roughly 6.0-year duration was 0.7 years shorter than the category median’s.A less-than-peer-median duration helped offset the portfolio’s increased credit risk from the end of 2021’s third quarter to the beginning of 2022’s fourth quarter. While BBB credit spreads widened from 107 basis points on Sept. 29, 2021, to 210 basis points on Oct. 12, 2022, the yield on the 10-year Treasury also rose from about 1.5% to 3.9%. The fund’s admiral shares lost 17.5% cumulatively over that period, which placed in the peer group’s top quartile.A repeat of the fund’s defensive showing during bond market turbulence isn’t guaranteed, however. When credit spreads widen, interest rates typically fall. In an environment like that, the fund’s greater credit sensitivity and below-median interest-rate sensitivity would both act as comparative headwinds.Ken Noguchi, analyst