5 1 efh12312002.txt FORM 5 EFH12-31-02 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 5 ANNUAL STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP [ ] Check box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. [ ] Form 3 Holdings Reported [ ] Form 4 Transactions Reported 1. Name and Address of Reporting Person(s) HEIZER EDGAR F. 261 BLUFF'S EDGE DRIVE LAKE FOREST, IL 60045 2. Issuer Name and Ticker or Trading Symbol Chesapeake Energy Corporation (CHK) 3. I.R.S. Identification Number of Reporting Person, if an entity (Voluntary) 4. Statement for Month/Year 12/02 5. If Amendment, Date of Original (Month/Year) 6. Relationship of Reporting Person(s) to Issuer (Check all applicable) [X] Director [ ] 10% Owner [ ] Officer (give title below) [ ] Other (specify below) Director 7. Individual or Joint/Group Filing (Check Applicable Line) [X] Form filed by One Reporting Person [ ] Form filed by More than One Reporting Person

SIGNATURE OF REPORTING PERSON /S/ By: Jennifer M. Grigsby For: Edgar F. Heizer, Jr. DATE 02/02/03

HEIZER EDGAR JR 5