Company: IPGP
Filing Date: 2025-05-21
Form Type: S-8 POS
Source: 0001111928-25-000082
Chunk: 0

Company: IPG PHOTONICS CORP
Filing Date: 2025-05-21
Form: S-8 POS
Chunk 0
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<div align='center'>As filed with the United States Securities and Exchange Commission on May 20, 2025</div>

#### Registration No. 333-139509

#### Registration No. 333-177818

#### Registration No. 333-206931

#### Registration No. 333-273640
| UNITED STATES                      
 SECURITIES AND EXCHANGE COMMISSION |

#### Washington, D.C. 20549
<div align='center'>____________________</div>

#### POST EFFECTIVE AMENDMENT NO. 1 TO

#### FORM S-8 REGISTRATION STATEMENT N
<div align='center'>O.</div>

#### 333-139509

#### FORM S-8 REGISTRATION STATEMENT NO. 333-177818

#### FORM S-8 REGISTRATION STATEMENT NO. 333-206931

#### FORM S-8 REGISTRATION STATEMENT NO. 333-273640

#### Under The Securities Act of 1933
#### __________________________

### IPG PHOTONICS CORPORATION
<div align='center'>(Exact name of registrant as specified in its charter)</div>

| Delaware                                       |     |             04-3444218 |
| (State or other jurisdiction of                |     |       (I.R.S. Employer |
| incorporation or organization)                 |     | Identification Number) |
| 377 Simarano Drive, Marlborough, Massachusetts |     |                  01752 |
| (Address of principal executive offices)       |     |              -Zip code |

<div align='center'>IPG Photonics Corporation 2006 Incentive Compensation Plan

(As Amended and Restated May 23, 2023)

IPG Photonics Corporation 2025 Incentive Compensation Plan

(Full Title of the Plan)</div>

#### Angelo P. Lopresti, Esq.
<div align='center'>Senior Vice President, General Counsel and Secretary</div>

#### IPG Photonics Corporation

#### 377 Simarano Drive

#### Marlborough, Massachusetts 01752
<div align='center'>(508) 373-1100

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copy to:</div>

#### Stuart M. Cable, Esq.

#### Joseph C. Theis, Jr., Esq.

#### Goodwin Procter LLP

#### 100 Northern Avenue

#### Boston, Massachusetts 02210
<div align='center'>(