IRTC · iRhythm Holdings, Inc.

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).

Mr. Patterson is voluntarily reporting the acquisition of shares of the Issuer's common stock pursuant to the Issuer's 2016 Employee Stock Purchase Plan for the purchase period December 1, 2025 through May 31, 2026. This transaction is exempt from Section 16(b) under Rule 16b-3.

Mr. Blackford is voluntarily reporting the acquisition of shares of the Issuer's common stock pursuant to the Issuer's 2016 Employee Stock Purchase Plan for the purchase period December 1, 2025 through May 31, 2026. This transaction is exempt from Section 16(b) under Rule 16b-3.

Mr. Rosenbaum is voluntarily reporting the acquisition of shares of the Issuer's common stock pursuant to the Issuer's 2016 Employee Stock Purchase Plan for the purchase period December 1, 2025 through May 31, 2026. This transaction is exempt from Section 16(b) under Rule 16b-3.

Mr. Freeman is voluntarily reporting the acquisition of shares of the Issuer's common stock pursuant to the Issuer's 2016 Employee Stock Purchase Plan for the purchase period December 1, 2025 through May 31, 2026. This transaction is exempt from Section 16(b) under Rule 16b-3.

Ms. Shrishrimal is voluntarily reporting the acquisition of shares of the Issuer's common stock pursuant to the Issuer's 2016 Employee Stock Purchase Plan for the purchase period December 1, 2025 through May 31, 2026. This transaction is exempt from Section 16(b) under Rule 16b-3.

Mr. Turakhia is voluntarily reporting the acquisition of shares of the Issuer's common stock pursuant to the Issuer's 2016 Employee Stock Purchase Plan for the purchase period December 1, 2025 through May 31, 2026. This transaction is exempt from Section 16(b) under Rule 16b-3.

These securities are restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of IRTC Common Stock. The vesting occurs on the earlier of (i) one year after grant or the (ii) the date of the company's next annual meeting.

These securities are restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of IRTC Common Stock. The vesting occurs on the earlier of (i) one year after grant or the (ii) the date of the company's next annual meeting.

These securities are restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of IRTC Common Stock. The vesting occurs on the earlier of (i) one year after grant or the (ii) the date of the company's next annual meeting.

These securities are restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of IRTC Common Stock. The vesting occurs on the earlier of (i) one year after grant or the (ii) the date of the company's next annual meeting.

These securities are restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of IRTC Common Stock. The vesting occurs on the earlier of (i) one year after grant or the (ii) the date of the company's next annual meeting.

These securities are restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of IRTC Common Stock. The vesting occurs on the earlier of (i) one year after grant or the (ii) the date of the company's next annual meeting.

These securities are restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of IRTC Common Stock. The vesting occurs on the earlier of (i) one year after grant or the (ii) the date of the company's next annual meeting.

All transactions reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan established by Mr. Talwalkar on May 12, 2025.

Represents the weighted-average sale price per share of a series of transactions, all of which were executed on May 11, 2026. The actual sale prices ranged from a low of $116.62 to a high of $117.31, inclusive. Mr. Talwalkar undertakes to provide upon request of the SEC staff, iRhythm Holdings, Inc. or any security holder of iRhythm Holdings, Inc., full information regarding the numbers of shares sold at each price within the range. The weighted-average sale price reflected has been rounded to 4 decimal points.

All transactions reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan established by Mr. Talwalkar on May 12, 2025.

All transactions reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan established by Mr. Talwalkar on May 12, 2025.

The option, originally granted on May 23, 2016 for 21,248 shares, vested in thirty-six equal monthly installments. This option has an expiration date of May 23, 2026. The Rule 10b5-1 trading plan of Mr. Talwalkar solely covers shares subject to options expiring in 2026 and 2027.

All transactions reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan established by Mr. Talwalkar on May 12, 2025.

Represents the weighted-average sale price per share of a series of transactions, all of which were executed on May 11, 2026. The actual sale prices ranged from a low of $115.61 to a high of $116.61, inclusive. Mr. Talwalkar undertakes to provide upon request of the SEC staff, iRhythm Holdings, Inc. or any security holder of iRhythm Holdings, Inc., full information regarding the numbers of shares sold at each price within the range. The weighted-average sale price reflected has been rounded to 4 decimal points.

All transactions reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan established by Mr. Talwalkar on May 12, 2025.

Represents the weighted-average sale price per share of a series of transactions, all of which were executed on May 11, 2026. The actual sale prices ranged from a low of $118.70 to a high of $119.63, inclusive. Mr. Talwalkar undertakes to provide upon request of the SEC staff, iRhythm Holdings, Inc. or any security holder of iRhythm Holdings, Inc., full information regarding the numbers of shares sold at each price within the range. The weighted-average sale price reflected has been rounded to 4 decimal points.

All transactions reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan established by Mr. Talwalkar on May 12, 2025.

Represents the weighted-average sale price per share of a series of transactions, all of which were executed on May 11, 2026. The actual sale prices ranged from a low of $117.68 to a high of $118.45, inclusive. Mr. Talwalkar undertakes to provide upon request of the SEC staff, iRhythm Holdings, Inc. or any security holder of iRhythm Holdings, Inc., full information regarding the numbers of shares sold at each price within the range. The weighted-average sale price reflected has been rounded to 4 decimal points.

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).

The sale reported on this Form 4 was effected pursuant to a Rule 10b5-1 trading plan established by the reporting person on November 19, 2025.

These securities are restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. 33.33% of the RSUs vest on March 12, 2027 and each one-year anniversary thereafter, subject to the Reporting Person continuing as a service provider through each such date.

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).

These shares were sold to cover tax withholding and remittance obligations in connection with the vesting of Restricted Stock Units (RSUs).