Rambus Inc.

Supplemental Reconciliation of GAAP to Non-GAAP Results

(Unaudited)

Three Months Ended

September 30,

(In thousands)

2021

2020

Cost of product revenue

$

13,157

$

9,661

Adjustment:

Stock-based compensation expense

(101)

—

Non-GAAP cost of product revenue

$

13,056

$

9,661

Total operating expenses

$

58,161

$

54,151

Adjustments:

Stock-based compensation expense

(7,381)

(6,834)

Acquisition-related costs and retention bonus expense

(1,658)

(1,327)

Amortization of acquired intangible assets

(359)

(236)

Expense on abandoned operating leases

(521)

—

Non-GAAP total operating expenses

$

48,242

$

45,754

Interest and other income (expense), net

$

54

$

968

Adjustments:

Interest income related to significant financing component from fixed-fee patent and
technology licensing arrangements

(2,163)

(3,379)

Non-cash interest expense on convertible notes

1,927

1,823

Non-GAAP interest and other income (expense), net

$

(182)

$

(588)

Rambus Inc.

Reconciliation of GAAP Forward-Looking Estimates to Non-GAAP Forward-Looking Estimates

(Unaudited)

2021 Fourth Quarter Outlook

Three Months Ended

December 31, 2021

(In millions)

Low

Forward-looking operating costs and expenses

$

79.9

$

75.9

Adjustments:

Stock-based compensation expense

(8.0)

(8.0)

Amortization of acquired intangible assets

(3.9)

(3.9)

Forward-looking Non-GAAP operating costs and expenses

$

68.0

$

64.0

Forward-looking interest and other income (expense), net

$

(1.0)

$

(1.0)

Adjustments:

Interest income related to significant financing component from fixed-fee patent and
technology licensing arrangements

(1.9)

(1.9)

Non-cash interest expense on convertible notes

1.9

1.9

Forward-looking Non-GAAP interest and other income (expense), net

$

(1.0)

$

(1.0)