Inclusion Criteria:

• 1. Age greater than 18 years.
• 2. GFR estimated by CKD-EPI formula \< 45 ml/min/1.73 m2 but ≥ 15 mL/min/1.73 m2 using IDMS-calibrated creatinine.
• 3. Hypertension. Using AOBP monitoring, BP of ≥ 130/80 mmHg.
• 4. Treatment with antihypertensive drugs: This would require the use of at least one antihypertensive drug. One of the drugs should be either an ACE inhibitor or ARB or a beta-blocker at the time of randomization.
• 5. Serum K 3.5 to 5.2 mEq/L at the time of randomization. In patients with eGFR \< 45 ml/min/1.73 m2 and serum K \> 5.2 mEq/L

Exclusion Criteria:

• 1. Use of spironolactone, eplerenone, amiloride, triamterene, thiazides, or thiazide-like drugs or the use of K supplements or K binders in the previous 12 weeks.
• 2. Expected to receive renal replacement therapy within the next 6 months.
• 3. Myocardial infarction, heart failure hospitalization, or stroke ≤ 12 weeks prior to randomization.
• 4. Pregnant or breastfeeding women or women who are planning to become pregnant or those not using a reliable form of contraception (oral contraceptives. condoms and diaphragms will be considered reliable).
• 5. Known hypersensitivity to thiazide or spironolactone.
• 6. Clinic AOBP \<110 mmHg systolic at their first visit