Exhibit 99.4

ARIZONA PUBLIC SERVICE COMPANY
NON-GAAP FINANCIAL MEASURE RECONCILIATION — OPERATING INCOME
(GAAP MEASURE) TO GROSS MARGIN (NON-GAAP FINANCIAL MEASURE)
(in thousands)

	THREE MONTHS ENDED				Pretax		After Tax
	SEPTEMBER 30,				Increase		Increase
	2005		2004		(Decrease)		(Decrease)
RECONCILIATION OF GROSS MARGIN
Operating Income (closest GAAP measure)	$	174,415	$	129,682	$	44,733	$	27,122
Plus:
Operations and maintenance		149,198		143,338		5,860		3,553
Depreciation and amortization		81,701		81,177		524		318
Income taxes		88,984		57,137		31,847		19,309
Other taxes		34,407		29,013		5,394		3,270
Gross margin	$	528,705	$	440,347	$	88,358	$	53,572

ARIZONA PUBLIC SERVICE COMPANY
NON-GAAP FINANCIAL MEASURE RECONCILIATION — OPERATING INCOME
(GAAP MEASURE) TO GROSS MARGIN (NON-GAAP FINANCIAL MEASURE)
(in thousands)

	NINE MONTHS ENDED				Pretax			After Tax
	SEPTEMBER 30,				Increase			Increase
	2005		2004		(Decrease)			(Decrease)
RECONCILIATION OF GROSS MARGIN
Operating Income (closest GAAP measure)	$	328,479	$	280,336	$	48,143		$	29,189
Plus:
Operations and maintenance		429,806		396,121		33,685			20,423
Depreciation and amortization		240,723		258,410		(17,687	)		(10,724	)
Income taxes		147,136		106,870		40,266			24,413
Other taxes		97,174		86,467		10,707			6,492
Gross margin	$	1,243,318	$	1,128,204	$	115,114		$	69,793