Blackstone Infrastructure Advisors L.L.C. New York, NY 10154 Attention: John G. Finley Email: john.finley@blackstone.com Ladies and Gentlemen:

Exhibit ▇▇

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▇▇▇▇▇▇▇▇▇▇ Infrastructure Advisors L.L.C.

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▇▇▇ ▇▇▇▇, ▇▇ ▇▇▇▇▇

Attention: ▇▇▇▇ ▇. ▇▇▇▇▇▇

Email: ▇▇▇▇.▇▇▇▇▇▇@▇▇▇▇▇▇▇▇▇▇.▇▇▇

Ladies and Gentlemen:

Reference is made to that certain Purchase Agreement (“Purchase Agreement”), dated as of January 30, 2019, by and among Tallgrass Energy Holdings, LLC, a Delaware limited liability company (“Holdings”), the other sellers named therein (together with Holdings, each a “Seller” and collectively, the “Sellers”), Prairie GP Acquiror LLC, a Delaware limited liability company (“GP Acquiror”), Prairie ECI Acquiror LP, a Delaware limited partnership (“Up-C Acquiror 1”), Prairie VCOC Acquiror LP, a Delaware limited partnership (“Up-C Acquiror 2” and, together with Up-C Acquiror 1, “Up-C Acquirors”), and Prairie Non-ECI Acquiror LP, a Delaware limited partnership (“Class A Acquiror” and, together with GP Acquiror and Up-C Acquirors, each an “Acquiror” and collectively, the “Acquirors”), and ▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇, ▇▇., ▇▇▇▇ ▇. ▇▇▇▇▇▇▇ and ▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇, in their respective capacities as Seller Representatives (each, a “Seller Representative” and collectively, the “Seller Representatives”). Each capitalized term used herein but not defined shall have the meaning ascribed to such term in the Purchase Agreement.

The purpose of this letter agreement (this “Side Letter”) is to confirm the understanding of the Sellers and the Acquirors with respect to certain matters related to the Purchase Agreement. Accordingly, in consideration of the mutual agreements contained herein, the parties hereby agree as follows:

1.    ▇▇▇▇▇ Trust. The ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇ Revocable Trust, under trust agreement dated August 27, 2013 (“▇▇▇▇▇ Trust”) will not sell any of its Class A Shares under the Purchase Agreement and is no longer a Party to, or bound by the terms and obligations of, the Purchase Agreement for any purpose. Accordingly, all references to the “▇▇▇▇▇ Trust” in the Purchase Agreement (including the exhibits thereto) are hereby omitted.

2.    DGD Class A Shares. The ▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇, ▇▇. Revocable Trust, a revocable trust under trust agreement dated April 26, 2006 (“DGD Trust”), will not sell any of its Class A Shares under the Purchase Agreement and all references to the “DGD Class A Shares” in the Purchase Agreement are hereby omitted. DGD Trust shall remain a Seller under the Purchase Agreement with respect to its Up-C Interests as set forth on Schedule 2.1 hereto.

3.    Seller Notes. Promissory Notes will not be issued by Class A Acquiror, Up-C Acquiror 1 or Blackstone Infrastructure Partners V L.P. to certain of the Sellers at Closing, or otherwise in connection with the Purchase Agreement. Accordingly, all references to “Seller Notes” and “Exhibit D” in the Purchase Agreement are hereby omitted.

4.    Purchase Price and Other Schedules.

5.    Wires. Notwithstanding anything to the contrary in the Purchase Agreement, each Seller acknowledges and agrees that the payments at the Closing made pursuant to the funds flow attached hereto as Exhibit E satisfy the Acquirors’ payment obligations under Section 2.1 of the Purchase Agreement.

6.    Effect of Side Letter. Except as otherwise expressly provided herein, all of the respective terms and conditions of the Purchase Agreement remain unchanged and continue in full force and effect. In the case of any conflict between this Side Letter and the Purchase Agreement, the terms of this Side Letter will govern. This Side Letter shall be deemed to be in full force and effect from and after the execution of this Side Letter by the parties.

7.    Governing Law. This Side Letter shall be governed by and construed in accordance with the laws of the State of Delaware, without regard to the principles of conflicts of laws thereof.

8.    Counterparts. This Side Letter may be executed and delivered (including by facsimile or other electronic transmission) in one or more counterparts, and by the different parties hereto in separate counterparts, each of which when executed shall be deemed to be an original, but all of which taken together shall constitute one and the same agreement.

[Signature Pages Follow]

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If the foregoing correctly sets forth your understanding of our agreement with respect to the matters above, please indicate your acceptance and approval below.

Signature Page to Side Letter re: Purchase Agreement

Signature Page to Side Letter re: Purchase Agreement

Signature Page to Side Letter re: Purchase Agreement

Acknowledged and agreed:

ACQUIRORS:

PRAIRIE GP ACQUIROR LLC

By: Prairie Non-ECI Acquiror LP, its sole member

By: BIP Holdings Manager L.L.C., its general partner

PRAIRIE ECI ACQUIROR LP

By: BIP Holdings Manager L.L.C., its general partner

PRAIRIE VCOC ACQUIROR LP

By: BIP Holdings Manager L.L.C., its general partner

PRAIRIE NON-ECI ACQUIROR LP

By: BIP Holdings Manager L.L.C., its general partner

Signature Page to Side Letter re: Purchase Agreement

Acknowledged and agreed:

Signature Page to Side Letter re: Purchase Agreement