MFS Income Fund

MFS Series Trust VIII · 5 share classes

Actively managed U.S. bond fund
One fund, 5 share classes:MFIOXMIOBXMIOCXMFIIXMFIWX
$8.20B NAV
528 positions · as of 2026-04-30 · filed 2026-06-29

Fund classification

Classified from what the fund holds · as of 2026 Q2

MFS Income Fund is an actively managed U.S. bond fund.

Asset class
Bonds
Region
United States
Management
Actively managed
Fund type
Open-end fund
Credit quality
Mixed credit
Rate sensitivity
Intermediate duration

Fund profile

As filed in the prospectus · 2026 Q1

The funds investment objective is to seek total return with an emphasis on high current income, but also considering capital appreciation.

Strategy · summarised

The fund invests primarily in a broad range of debt instruments across corporate, government, and emerging market issuers, with up to 35% in below investment grade securities, and allocates across corporate debt, mortgage-backed securities, asset-backed securities, and government bonds with an emphasis on fundamental analysis of individual instruments. The fund may concentrate a significant portion of assets in a single issuer, sector, or country, creating concentration risk. The fund may purchase or sell securities on a when-issued or forward commitment basis, including mortgage-backed securities in the TBA market.

Expenses
0.40% 1.48%across 5 share classes
Share classGrossNet
MFIOX0.80%0.73%
MIOBX1.55%1.48%
MIOCX1.55%1.48%
MFIIX0.55%0.48%
MFIWX0.46%0.40%

Net is what a holder pays after the adviser's contractual waiver; gross is before it. A waiver can expire.

Portfolio turnover 26.00% · as of 2026 Q1

Allocation

Asset groups · long / short shown separately, never netted · 2026 Q2

99.50%
of net assets
Bonds70.01%
Securitized27.80%
Cash & short-term1.83%
Derivatives-0.15%

The outer band is exposure held short — written against the portfolio rather than part of it, which is why it sits outside the ring and why the two are never netted into one figure.

Derivatives are shown at market value, not notional exposure.

Sector allocation

The same holdings as Allocation above, grouped by market sector instead of asset type · as of 2026 Q2

100%
of net assets
Government29.9%
Securitized27.9%
Other12.3%
International9.5%
12 smaller20.4%

Government, Securitized and Cash are non-corporate buckets; International is foreign holdings we don’t sector-classify, and Other is the residual (held funds, unresolved names).

Latest quarter

What changed since the fund's previous filing

2026Q2 vs 2026Q1: 42 new31 exited

Largest new: New Residential Mortgage Loan Trust, PMT Loan Trust, Bain Capital Credit CLO Ltd., Venture 43 CLO Ltd., Massachusetts Development Finance Agency, Morgan Stanley Residential Mortgage Loan Trust, Salesforce, Inc., Oracle Corp.

Largest exited: United States of America ×2, Bain Capital Credit CLO Ltd., Venture 43 CLO Ltd., OZLM XXI Ltd., NCL Corp. Ltd., Rio Tinto Finance USA plc, LKQ Corp.

Return profile

Chart:

Total return as filed — price change plus distributions reinvested · trailing figures to Apr 2026

Share class1-year3-year5-yearVolWorst fall
+4.95%+13.97%+4.17%3.20%-5.14%
+4.15%+11.40%+0.37%3.19%-5.54%
+4.16%+11.58%+0.50%3.44%-5.42%
+5.21%+14.81%+5.45%3.42%-5.04%
+5.29%+15.30%+5.92%3.41%-4.82%

These classes hold the same portfolio, so the 5.55pp spread over 5 years is the cost difference between them — roughly 1.11pp a year — not a difference in what they own.

Cumulative return· May 2023 – Apr 2026

Debt profile

What this fund holds — value-weighted across its bond and securitized long positions · as of 2026-04-30

Avg coupon
5.38%
Avg maturity
13.21 yr
Coupon type

Share of the fund's debt by how its coupon behaves — the fact that decides whether a rate move reaches this portfolio at all.

34%
floating
Fixed rate65.7%
Floating rate34.3%
Maturity ladder

Share of the fund's debt value in each maturity band, shortest first.

<1y10y+
<1y1.8%
1-3y6.5%
3-5y11.0%
5-10y35.4%
10y+45.2%
Flagged holdings
Defaulted: 0.12% · $9.85M · 2 positions
In arrears: none reported
Paid in kind: 0.56% · $44.84M · 3 positions

These three overlap — one holding can be in arrears and paying in kind at once — so they are shown separately and never summed.

Risk profile

Interest-rate and credit-spread sensitivity, both in years · as of 2026Q2

Most of this fund’s sensitivity is to interest rates, with credit spreads carrying about half as much.

Interest-rate duration
5.67 yr
approx. move per 100bp
Credit-spread duration
2.88 yr
approx. move per 100bp
If rates and spreads both rise 100bp

Where the loss would come from. The two shocks are the same size, so this is the balance of the fund's two sensitivities rather than a bet on one moving more.

≈ -8.5%
of value
Interest rates66%
Credit spreads34%

Filers report the impact of a 0.01% move only, so the total is our own scaling of that one number and overstates the loss on most bonds — read it as approximate, never as precise. The two sensitivities overlap rather than add up: they measure the same positions against different shocks, which is why the durations above are shown side by side and never summed.

Credit risk by quality

Share of the fund's spread duration carried by each credit tier.

+2.88
yrs total
Investment grade+2.26 yr
High yield+0.62 yr
Where the risk sits on the curve

Share of duration at each point, shortest first. A positive figure loses value when spreads widen; a negative one offsets — a credit hedge.

Interest rate5.67 yr total
3 mo30 yr
3 mo0.01 yr0%
1 yr0.61 yr11%
5 yr1.62 yr29%
10 yr2.23 yr39%
30 yr1.21 yr21%
Credit spread2.88 yr total
3 mo30 yr
3 mo0.02 yr1%
1 yr0.42 yr14%
5 yr1.29 yr45%
10 yr1.06 yr37%
30 yr0.10 yr3%

The two bands measure the same positions against different shocks and do not add — a Treasury carries rate duration and no spread duration, a floating-rate credit the reverse. Rate tenors are also summed across every currency the fund discloses.

Show the numbers
TenorRate yrsIG yrsHY yrsIG $/bpHY $/bp
3 mo+0.01+0.01+0.01$9.3k$4.6k
1 yr+0.61+0.24+0.17$198.8k$142.2k
5 yr+1.62+0.97+0.32$794.3k$265.7k
10 yr+2.23+0.95+0.11$782.9k$87.6k
30 yr+1.21+0.08+0.01$69.1k$11.1k

Dollar change per 1bp of spread movement, as filed and sign-anchored. A blank cell was not filed; a zero was.

Rate exposure by currency

Duration contribution in years, summing to the fund's 5.67 yr.

USD+5.67 yr
EUR+0.00 yr

This is where the fund's rate exposure sits, not its currency risk — most international bond funds hedge the currency back to dollars, and the size of those hedges is not in the filing. Tenors are also summed across curves, so a 5-year JPY point and a 5-year USD point are added together.

Holdings

By % of NAV · equity positions carry filed share counts · every resolvable issuer links to its company page

Issuer%NAVValue
United States of America4.50% · due 2044-02-152.93%$240.57M
United States of America4.75% · due 2043-11-152.37%$194.56M
United States of America4.63% · due 2029-04-302.19%$179.48M
United States of America4.88% · due 2045-08-151.98%$162.22M
United States of America4.75% · due 2045-02-151.86%$152.86M
MFS Institutional Money Market Portfolio1.83%$150.23M
United States of America4.25% · due 2054-02-151.81%$148.85M
United States of America4.13% · due 2028-07-311.74%$142.80M
United States of America4.50% · due 2027-04-151.74%$142.37M
United States of America4.50% · due 2054-11-151.71%$140.31M
Showing 10 of 528Sign in to see more

Top 10 positions are 20.17% of net assets, top 25 30.73%, across 277 issuers.

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