# EDGAR Filing Document

**Accession Number:** 0000770540
**File Stem:** 0001193125-25-142595
**Filing Date:** 2025-6
**Character Count:** 8784
**Document Hash:** 95d519ac3b5248cbdbf23170daf49651
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-25-142595.hdr.sgml**: 20250618

**ACCESSION NUMBER**: 0001193125-25-142595

**CONFORMED SUBMISSION TYPE**: 497

**PUBLIC DOCUMENT COUNT**: 11

**FILED AS OF DATE**: 20250618

**DATE AS OF CHANGE**: 20250618

**EFFECTIVENESS DATE**: 20250618

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Natixis Funds Trust I
- **CENTRAL INDEX KEY:** 0000770540

**ORGANIZATION NAME:**
- **EIN:** 000000000
- **STATE OF INCORPORATION:** MA
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 497
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 002-98326
- **FILM NUMBER:** 251056223

**BUSINESS ADDRESS:**
- **STREET 1:** 888 BOYLSTON STREET
- **STREET 2:** 8TH FLOOR
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02199
- **BUSINESS PHONE:** 617-449-2810

**MAIL ADDRESS:**
- **STREET 1:** 888 BOYLSTON STREET
- **STREET 2:** 8TH FLOOR
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02199

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** IXIS Advisor Funds Trust I
- **DATE OF NAME CHANGE:** 20050502

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** CDC NVEST FUNDS TRUST I
- **DATE OF NAME CHANGE:** 20010503

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** NVEST FUNDS TRUST I
- **DATE OF NAME CHANGE:** 20000202

## Series and Classes Contracts Data

### Loomis Sayles Core Plus Bond Fund (Series ID: S000006660)

---

|  |  |  |
|:---|:---|:---|
| Class Name | Ticker Symbol | Class ID   |
| Class A    | NEFRX         | C000018168 |
| Class C    | NECRX         | C000018170 |
| Class Y    | NERYX         | C000018171 |
| Class N    | NERNX         | C000125481 |
| Class T    | LCPTX         | C000188560 |

---

## Series and Classes Contracts Data

### Loomis Sayles Core Plus Bond Fund (Series ID: S000006660)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000018168 | Class A      | NEFRX           |
| C000018170 | Class C      | NECRX           |
| C000018171 | Class Y      | NERYX           |
| C000125481 | Class N      | NERNX           |
| C000188560 | Class T      | LCPTX           |

?xml version='1.0' encoding='ASCII'? Natixis Funds Trust I

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*Supplement dated June 18, 2025 to the Prospectus and Summary Prospectus, each dated February 1, 2025, as may be revised or supplemented from time to time, for the following fund:* 

#### LOOMIS SAYLES CORE PLUS BOND FUND

#### (the "Fund")
Effective July 1, 2025, Loomis, Sayles & Company, L.P. has given a binding contractual undertaking to the Fund to limit the amount of the Fund's total annual fund operating expenses to 0.73%, 1.48%, 0.43%, 0.73% and 0.48% of the Fund's average daily net assets for Class A, Class C, Class N, Class T and Class Y shares, respectively, exclusive of brokerage expenses, interest expense, taxes, acquired fund fees and expenses, organizational and extraordinary expenses, such as litigation and indemnification expenses. This undertaking is in effect through January 31, 2027.

***Accordingly, the Annual Fund Operating Expenses table and the Example table within the section "Fund Fees & Expenses" of the Summary Prospectus are amended and restated as follows with respect to the Fund:***

#### Annual Fund Operating Expenses
*(expenses that you pay each year as a percentage of the value of your investment)* 

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class A** | **Class C** | **Class N** | **Class T** | **Class Y** |
|  Management fees | 0.32% | 0.32% | 0.32% | 0.32% | 0.32% |
|  Distribution and/or service (12b-1) fees | 0.25% | 1.00% | 0.00% | 0.25% | 0.00% |
|  Other expenses | 0.18% | 0.18% | 0.07% | 0.18%<sup>1</sup> | 0.18% |
|  Total annual fund operating expenses | 0.75% | 1.50% | 0.39% | 0.75% | 0.50% |
|  Fee waiver and/or expense reimbursement<sup>2</sup> | 0.02% | 0.02% | 0.00% | 0.02% | 0.02% |
|  Total annual fund operating expenses after fee waiver and/or expense reimbursement | 0.73% | 1.48% | 0.39% | 0.73% | 0.48% |

---

<sup>1</sup> Other expenses for Class T shares are estimated for the current fiscal year

<sup>2</sup> Loomis, Sayles & Company, L.P. ("Loomis Sayles" or the "Adviser") and Natixis Advisors, LLC ("Natixis Advisors"), the Fund's advisory administrator, have given a binding contractual undertaking to the Fund to limit the amount of the Fund's total annual fund operating expenses to 0.73%, 1.48%, 0.43%, 0.73% and 0.48% of the Fund's average daily net assets for Class A, Class C, Class N, Class T and Class Y shares, respectively, exclusive of acquired fund fees and expenses, brokerage expenses, interest expense, taxes, and organizational and extraordinary expenses, such as litigation and indemnification expenses. This undertaking is in effect through January 31, 2027 and may be terminated before then only with the consent of the Fund's Board of Trustees. The Adviser will be permitted to recover, on a class-by-class basis, management fees waived and/or expenses reimbursed to the extent that expenses in later periods fall below both (1) the class' applicable expense limitation at the time such amounts were waived/reimbursed and (2) the class' current applicable expense limitation. The Fund will not be obligated to repay any such waived/reimbursed fees and expenses more than one year after the end of the fiscal year in which the fees or expenses were waived/reimbursed. 

#### Example
This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods (except where indicated). The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same, except that the examples for the Class A, Class C, Class T and Class Y shares are based on the Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement

------

assuming that such waiver and/or reimbursement will only be in place through the date noted above and on the Total Annual Fund Operating Expenses for the remaining periods. The example for Class C shares for the ten-year period reflects the conversion to Class A shares after eight years. The example does not take into account brokerage commissions and other fees to financial intermediaries that you may pay on your purchases and sales of shares of the Fund. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

---

| | | | | |
|:---|:---|:---|:---|:---|
| **If shares are redeemed:** | **1 year** | **3 years** | **5 years** | **10 years** |
|  Class A | $496 | $651 | $821 | $1313 |
|  Class C | $251 | $471 | $815 | $1585 |
|  Class N | $40 | $125 | $219 | $493 |
|  Class T | $323 | $481 | $653 | $1154 |
|  Class Y | $49 | $157 | $276 | $625 |

---

---

| | | | | |
|:---|:---|:---|:---|:---|
| **If shares are not redeemed:** | **1 year** | **3 years** | **5 years** | **10 years** |
|  Class C | $151 | $471 | $815 | $1585 |

---

------

*Supplement dated June 18, 2025 to the Statement of Additional Information, dated February 1, 2025, as may be revised or supplemented from time to time, for the following fund:* 

#### LOOMIS SAYLES CORE PLUS BOND FUND

#### (the "Fund")
Effective July 1, 2025, Loomis, Sayles & Company, L.P. has given a binding contractual undertaking to the Fund to limit the amount of the Fund's total annual fund operating expenses to 0.73%, 1.48%, 0.43% 0.73% and 0.48% of the Fund's average daily net assets for Class A, Class C, Class N, Class T and Class Y shares, respectively, exclusive of brokerage expenses, interest expense, taxes, acquired fund fees and expenses, organizational and extraordinary expenses, such as litigation and indemnification expenses. This undertaking is in effect through January 31, 2027.

#### Accordingly, the table regarding expense limits within the section "Fund Charges and Expenses" is amended and restated as follows with respect to the Fund:

---

| | | |
|:---|:---|:---|
| **Fund** | **Expense Limit** | **Date of Undertaking** |
|  ***Loomis Sayles Core Plus Bond Fund<sup>1</sup>***  |  | July 1, 2025 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Class A | 0.73% |  |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Class C | 1.48% |  |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Class N | 0.43% |  |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Class T | 0.73% |  |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Class Y | 0.48% |  |

---

<sup>1</sup> The expense caps above account for advisory administration fees payable to Natixis Advisors. Loomis Sayles and Natixis Advisors have agreed to equally bear the waiver/reimbursement.